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DICTIONARY OF CHEMISTRY. 



VOL. n. 



LOHDOH 

PBIHTBD BT BPOTT18WOODB ABU CO. 

BBW-flTBBBT BQUABB 



A DICTIONARY 

OF 

CHEMISTRY 

AMD THE 

ALLIED BRANCHES OF OTHER SCIENCES. 
Founded on that of the late Dr. Ure. 

BY 

HENRY WATTS, B.A., F.C.S. 

nmoB or 
' TBI rovUAL or TBI camioiL sooirt.' 

ASSISTED BY EMINENT CONTRIBUTOBa 
IN POUR VOLUMES. 

VOL. n. 
CONHYDRINE— OHGE. 



LONDOl^: 
LONGMAN, GREEN, LONGMAN, ROBERTS, & GREEN. 

NEW YORK: 

WILLIAM WOOD & CO., 61 WALKER STREET. 

1804. 






DICTIONARY OF CHEMISmY. 



COVBTSSZVa. C«H"NO, or C»«iP'^a«. (W ertheim, Wien,Akad, Ber. xidi. 
113.) — This alkaloid, which has the composition of a hydrate of conine (C*n'»N.H-0), 
exists, together with conine, in the flowers and ripe seeds of hemlock ( Conium fnaculatum). 
It is extracted by a process which will be described under Goninb, and purified from 
adhering conin'b by pressing the prodact after it has been submitted to a low tempera- 
ture (by means of a freezing mixture), and subsequently by repeated reciystallisation 
from ether. 100 kilogr. of fresh flowers ^eld 6 grammes of pure crystals. 

Conhydrine crystallises in laminse having a pearly lustre and splendid iridescence ; 
they melt at a gentle heat and sublime below 100° 0. It has a slight odour, which 
increases when the substance is Tolatilised, and closely resembles that of conine. Its 
aqueous and alcoholic solutions have a strong alkaline reaction. Its physiological action 
is narcotic, but less powerful than that of conine. 

1 pt of conhydrine, heated to 200° C. for an hour and a half with 3 pta. of anhy- 
drous phosphoric acid in a glass tube, decomposes into conine and water. 

Conhydrine neutralises acids, expels ammonia from its compounds, but appears to be 
separated from its salts by conine. The hydrochlorate is unciystallisable. 

Chioroplatiyiate, CH^'NO.HCLPtCP. — An alcoholic solution of conhydrine neutra- 
lised with hydrochloric acid is mixed with alcoholic dichloride of platinum, care being 
taken to avoid an excess of the latter, and the whole is placed over sulphuric acid in 
vacuo ; when crystals begin to form, the solution is removed to the air and allowed to 
evaporate, and the crystals are washed, first with ether-alcohol, then with ether. The 
salt crystallises in hyacinth-red tablets, from 1 to 4 millim. in length, belon^ng to 
the trimetric system. It gave by analysis 27*68 per cent C, 6-31 H, 4-66 N, and 
28-04 Pt, the formula requiring 2947 C, 6-16 H, 4*01 N, and 28'33 Pt 

OOVZCBA&OZXa. An arseno-phosphate of eopper and calcium, containing also 
a small quantity of vanadic acid, found at Hinajosa de Cordova in Andalusia. It 
forms reniform masses of pistachio-green colour inclining to emerald green, and yield- 
ing a streak of the same colour. Hardness — 4*6. Specific gravity — 4*123. Sub- 
translucent Brittle. Fracture splintery. It contains, according toiritzsche (Pogg. 
Ann. Ixxvii. 139), 30-68 per cent As*0*. 881 FH)^, 178 VK)», 31-76 CuH), 21-96 
CaH>, and 6*61 water, whence it may be regarded as 

tity of the arsenic or phosphoric acid being replaced by vanadic acid. (Dana, ii. 
421 ; Kammelsberg, p. 376.) 

COWZVa. QmHne, Cicuiine, G*H>*N, or 0**JEr«M— A Tolatile alkaloid which 
forms the poisonous principle of hemlock {Conium mcunUatum), It was discovered in 
1827 by Oiesecke (Brandes* Arch. Pharm. zz. 97), but was first prepaid in the 
xmie state by Geiger in 1831 (Mag. Pharm. zzxv. 72, 269 ; xxxvi. 169). Ortigoia 
(Ann. Ch. Pharm. xHi. 313) assigned to it the formula C^B}*Ni Blyth (Chem. 8oc 
On. J. i. 346) regarded it as O^H"N. The formula C^"N, according to which conine 
is isomeric with qranide of oenanthyl or capronitrile, C'H".CN, was proposed by 
Oerhardt and adopted by v. Planta and E6kul6 (Ann. Ch. Pharm. Ixzxiz. 129), 

Vol. IL ^ 



f«w « 



*^M9 



CONINE. 



\rho hare sliown that coBine exhibits tho characters of a secondMy mon amine 

Tho last formula, which wprpsente mmine as conteining tho mdicle btitywsyl C*H% 
is rendered probable by tho frequent produylion of butyric acid in tbe oxidutloE of 
Conine. 

Conine exists in combination vnth. acids in all parla of the hemlock pliuitj but mof^t 
abnndontiy in the fruit a little before maturity. The leares contain u TOueh «maller 
quantity, and appear t-o lose nearly tho whole of it in dryings whereas in the fruit tho 
quantity ia little, if at all, altered by desiccation. It occurs abo in the flowers. Ac- 
cording to Walz. conino i» probably also contained in the ripe seeds of foora parsley 
{.Eihusa Ci/namuw). Aooozding to Wagner, it appears to exist in the root <h 
ImperatoHa. In idl these plftots it exists in oombination with acirk, and mnst 
tht^rcfore be separated by the action of a stronger base. It then distils over paaily 
with Tapour of wat^n 

Preparation. — 1. The seeds erf hemlock are diBtilled with carbonat'C of potaasium or 
fllalced lime, and the yoDowish dititilltitj?^ upon which oily drops float, is neutralised 
with anlphorici acid and evaporated : it then bi-ioomes reid, violet, and lafltly brown* 
and deposits brown roainons flakes, which are separatvd by filtration. The Bltrata 
is evaporated to th© consistence of thick sjrrup, and the residue is treati.^ with a miiturt) 
of three ports aljsolute alcohol and one part ether, as loug as it continues to grow 
tarbid. A precipitate of snlphato of ammonia is thus fomiod, from which the liquid 
is filtered and then distilled ; and the residue is heated in a water-bath and I'eptiatodly 
moistened with water» until no mor« alcohobc Tapours are pereeptible. On cooling, 
the mass is found to contain a nrnnber of micaceous lamina*, which trannot Im separated. 
The whole is, therefore^ distilled with potash in a ehloridc-of-cali-ium bath, wher«*npoa 
a detir yellowiah oil first passes over, containing alcohol (probably from ethybsulphate 
of potaseium), and smelling strongly of oonine. If this product m rt?nd<?red txirbid by 
mixture witli the foUowinf^ distiilute, th© receiver mnst be changed, and the distillation 
continued till the residue h almost dry, when it is again to bo mixed with caustic 
polash and water, and distilled as long as conino continues to puss over. The distil- 
late, consisting of a watery liquid and oily conine, which still contains water in solution 
(Jor which ntuon it becomes turbid whfn heated), is mixed with chloride of calciuni as 
long as the latter continues to absorb water, and then distilled; ammonia is then 
Involved, and there remains a brown resinons residue. The flistillate ia again treated 
with chloride of calcium and dtetillod in a sand-bath, and the product, which is ahuost 
colonrlesSy is rectified alone ; it then lenves a small resinous residue. 6 Itje. of fn^h 
green, unripe aeeda, or & lbs. dry ripe ae<?ds» yield 1 as. conine* (Ge iger.) 

2. The npe seeds are ejthaust^ with alcohol, the alcohol is distilled ofiE] and the 
residual syrup is mixed with an equal volume of wat^r and a little hydrate of potaa^ 
sinni, and distilled in a chloride-of-calcium bath. (Chriitison.) 

3. When th© fresh flowers (or seeds) of hemlock are exhausted with hot wat«r to 
which a little sulphuric acid has been added, and the extract snpersaturatcd with lime or 
hydnttc of [KDfassium and distilled as rapidly as possible, a strongly alkaboe diiiiillsite, 
containing ammonia, conine, and oonhydrine passes over. The distillate is ncuti atiscKl 
with snlphnric add, evaporated on a water^bath to a thick syrupy consistence, and then 
treated with absolute alcohol, which precipitates sulphate of ammonia. The solution 
is removed from the deposit and placed on a wat«i--batli, in order to livaporate off tho 
alci^hol ; the residue is allowed to coc^l, then strongly Hupcraaturated with conct^u* 
t rated potash and mixed T^ith ether, thi? wholo being shaken for a considerable time 
The brownish red ethcre^d solution thus obtainod is separated from the aqueous solu- 
tion and evaporated on a wat*ir-bath, till the ether is completely driven off; it is 
finally heated to 100^ C, and then distilled in a stream of hydrogtn, at a very slowly 
increasing temperature, in an oil-bath. Conine rendered impure by a little water 
and ether, first passes over, and afterwards colourless oily conine, which may easily b« 
purified by neutralising with hydrochloric acid, pouring off tho mothcr-liquor from the 
crystals oi hydrochlorate of conine, and recryst^illising tlie salt from alcohoL Conhy- 
drine remains in the retort, and, on heating, sublimes in the upper part and net^k of 
the retort in cryBtalHrie lamina?; if very slowly he^ited, it sublimes at 15t}<^ C, otherwino 
between l&oo and 210°. (Wertbeim.) 

Purijication. — Conine, obtained by Ge Igor's process, may still contain ammonia. To 
remove this impurity, the product is shaken in a long gloss tulxj with wat^'r, and after 
ft lew hours, the conine is decant-ed off. The wash- water becomt»s milky on being 
■bakon up with chlorioe-wuter, but does not evolve nitrogen f^a3 if free fromi ammonia 
(Bonteoji'C h ar lard and Hen ry). The ammonia is rt^moved by placing the c<mine in 
vaeao over enlphuric acid ; the evolution of ga^-bubbles causes ebtdJition (Liebig). 
If the conine contains water^ it is mixed with insed hydmte of potassium ; tiie ooaino 




CONINE. 



B 



then leptfmtes out, aftor it time, in an oilj strattim, 'whkh m remoTed and rectiflrd ' 
nlone. Commercinl chloride of calcium ciiiinot bo used for this purpose, as it geacruUy 
oontaixif olcuaiiia* 

Proptrttet, — Conine is a limpid oily liquid of specific mvitj 0"89 (Geigor). 0*878 
(Blyth). It boilii at 168°— 171*^0. (Blyth) ; at 187-5^ a (Geiger); 189^0. (Chri»- 
t iBon); 212^C. (Ortigocia); oud wht-n carefully but rapidly heated, Aistiia almost with- 
cmt decomposition (Geiger). It Tolatiiisefi in vacuo ;it aniiDary icmp^nLturvs, and 
distill wiLoout residue (Licbigr, Ortigosa). It may bo carried over with iTipour 
of vnter at 100° C, but not without alight decomposition. It ha* a highly ponetratiug, 
repulsive, pr»culiarf and Buffocating odour, like that of tobacco, and somewhat resembling 
that of hemlock; at a diffitance, and in amall quantity, it funella like mice; if doaely 
inhaled, it attacks the head and prorctkea tears (Geiger). Its taste is sharp^ i^pul^ 
tftre, and peisiet'ent, Ule tbat of tobacco* It is a Tioleot poison, amall q^uantities of it 
rapidly canaing death, attended with tetanus. When outwardly applied* it doe» nfjt 
dilate the pupil, even if introduced into the ey« itself (Geig©rJ. (On the action of 
eonine, see Christison, J, Pharm. ixii, 413; J. Cliim. med. zii. 46L Kublmann^ 
N, Br. Arch. xxiiL 38.) It hiis a strong alkaline reaction, but only in the presence 
of water (Geip;er). The a] kaline reaction disa^tpeiLra from turmeric pap£X on application 
of heat, and slowly from Htmua paper. (Blyth.) 

The composition of conine is as follows : 

GuImmi 8 atoma 
Hydrogen Ifi *, 

Hitrogen 1 „ 




Sw duration, 
96 76-80 
15 1200 
14 11^20 


74-69 
1205 


7611 

13-oe 


125 ir>u-oo 







is slightly soluble in water at ordinary tempctcatnres ; it Is also capable of 

t one-third of its weight of water, and jit low temperatures an c^^uol weight ; 

rit 1m then heated, it becomea turbid, from separation of waAer (Geiger). It is very 

soluble in aicokat^ and when dissolved in 4 pb^* of alcohol, may be min^d in all projwr- 

*-on« with water. It is easily soluble in eihcr^ ia oiis^ both fixed and volatile, and in 

Conine dissolves tuJphur in large quantity, forming a dark oiazig»-coloufod solution, 

*iich yields crystals of sulphur hy evaporation- It is slightly somble in §uiphid« of 

rbon^ It does not appear to dissolve phosphorus^ 

I lhe&nipo&Uion&. — 1. Conine ia very iuflammnb^ and bums with a bright smoky 

'sme, like volatilQ oils, leaving only a small residue of carbon, (Geiger.) 

2. When kept &om tJio air, conine remains colourless, but, on exposure to the air, it 

pidiy turns yellow^ brown, and viscid, and becomes less soluble in water. The 

\ or alcoholic solution undergoes the same decomposition^ especially if the eoulnf^ 

i*, both rapiiily turn brown, while the aqueoos solution becomes turbifl, and 

resinous Hakes (Geiger). In the decompoBition of conine by tlit; air, ri'Hin 

ned and ammonia evolved (Christ ison). Conine, placed in a ^ihallow dish, 

exposed to the action of oxygen for some weeks, turns dark red, ttecrvmes thicker, 
i is finally converted into a stringy resinous mass, which smells strongly of coDine, 
I has an alkuline reaction. Tliis ro&in dissolves in strong hydrochloric acid, and is 
" litated by carbonate of potassium. If this operation be repeated, and the product 
1 with water, a reain is obt^iincil which is free from conine, smeUs of but^Tie acid 
L burnt or exposed to moist air, and contains nitrogen. (Blyth.) 
k 8. On dislilling conine, a portion is always dec^mposod^ anamonia boing evolved and 
III ifniBied. The purer the conine, the less decomposition takes place* Heated for 
t tjine to a temperature ne^ir its boiling pOLnt» it is nvach more decompoaod than when 
{ ia Ttk^diy hoaied to boiling, in which case the greater part distils over ud changed ; 
Miia and a nsin are formed, and perhaps also carbomc and acetic acids (Geiger)* 
t eoQUiev em^rated in vacuo over substances which attract moisture, leaves a 
I pitehy residue ( Ch a rl ar d and Henry, Ann. Ch. Phya. Ixi. 33 7 ). Moist conine 
reain on distUlation ; the- dry subBtAoco does not (Or tigosa, Ann. Ch, Pharm. 
13). When conine is heated atiove 172^ C„ the boiling point rapidly rises, de- 
aition takes place, and white fumes aro evolved. (Blyth.) 
4.' In the oriduiion of conine, butyric acid is generally formed, as when conine is 
Diled with nitric acid (a resin is formed at the same time, which is precipitated from 
lie solution by potash on cooling) ; also on eTa[iorating hydrohromate of conine in vacuo 
^th a slight excess of bromine, or by evaporating sulphate of conine to dryness^ and -by 
'm$ conine with acid chromate of potassium and sulphuric acid (Blyth). An 
|<of butyric a<?id is perceptible during the evaporation of the platinum- or mereury- 
coni'no, and of its basic substitution-products (v. Plant a and Kekule). Co- 
I ledttces ailver^^alta, (Ortigosa.) 

b2 



CONINE. 



5. When conine is neufraliiM^ viith dilui« mineral acids, it m not deomnpoiGd by 
spontanc^onji <!va|»oratiaa, but if p\'aj>onited with the aid of hpiit, its j^lutiovi beooniM 
*lnrk, and s salt of ammonia, and a resin jiri? formed, The sami" reai'tion ifl produjced, 
avr-ii in the cold, by an excess of iicid, or by act tic or tartaric acid* (Geiger.) 

6. Alt-oholic tinrture of todint acts Tioli^nVly upon moist contne, the solution becoming 
turbid and yellow for a few momeDt^i, and thi*n colourlc^, and ultimately drying up to 
iwi uncrystiUlisabk mass (Geiger,) A weak tincture of iwiine added drop by drop 
tn aleohoHe conine, produces a dark brown prfoipitate^ which disaolroB and formis a 
colourless liquid When tincture of iodine is added aj long as the liquid remaini 
eolourleaa (if an eicess of iodine is added, a different decomposition takes pliwc), and 
the solution eva|x>rated in vacuo, there retniiint a brownish mother-liquor, containing 
crystals of a similar form to those obtained by the action of bromine upon coaiiie ; they 
are easily soluble in water, alciohol, and ether (Elyth)u Anhydrous conine b<*- 
comea heated in contact with iodine* and formfi thick white fumes and ^i readily fusible 
mass, which Li at first blood-red, mid Afterw&rds tuma olive-green ; this l^^dy diaaolvcB 
in water, fommig a Bendy coiouri^aa Bolution, and depositing a thick black resin. 
(Geiger.) 

7. When conine (distilled at 169^ C) is exposed to vapour of braminf, it immediately 
Bolidifiefi into a muss of crj'stalline needles. If too much Ijroinine is uaed, the chief 

ftroduct itt a gummy mass ; if eonmo Is employed which distilled over below 1GS°, a red 
iquid IB formed. The purer the conine^ the more abundant is the formation of crysta.l». 
Conine which haj» passed over between 98^ and 136° does not at first form any cryetalj* 
with brf>mine^ and when evaporatiHl in vacuo, becomca dark red, or, if more bromine i^ 
added, black. This jiroduct, dissolved in water, boiled with &nimal chajrcoal* then fil- 
t^^j'ed and evaporated in racuo over enlpburic acid, yields tranapareDt colourless needle* 
and a brown mother-liquor. The crystali*, aitier waahing with ether, contain 48-62 per 
cent. C, and 8 '98 H; they are readily soluble in water and in alcohol, hut mucli less in 
ether ; when purified by treating them with ether» and recrystallised from water or from 
nlcoholi they focm needles which are permanent in the air and melt into an oil at alxiut 
100"'' C.„ giving off a little conine vapour. On cooling, the oil solidifies into a striated 
tnaas. (Blyth.) 

8. Anliydrous eonine, acted upon by chlorine gos^ gives off dense white fnmes, becomes 
hot and thick, and forms a dark broiAti muss, which has a peculiar odour, something like 
thatof chloriup, but not like that of CMinine, and when suspended in water and treated with 
caujstic BOKhv^ diffuses an odour of conine an<l turpentine. With bydrated conine, chlorino 
^as produces a whitish turbidity, separation of oO drops, and a smell of chloride of 

[ nitrogen; if potaah be then added, an odour of conine is evolved (Geiger), Moist 
Conine, free foim ammonia, does not evolve nitrogen when shaken with ehlorine-water 
(Charlard and H c n ry ). When chlorine gas is |>:issed ov er conuie wh i ch h as dist i 11 cd 
at 130° C, the coniue becomes hot, aussumes a djirk red colour, and emits heavy white 
Taf>ours which smell somewhat like oil of lemon. If the action of the chlorine be con- 
tinued and the oil cooled, it become^ colourless again and thicker, ceases to evolve white 
Vrtfiours, and Ixecomes covtred with white crystals, into which it is completefly converted 
aftiir the chlorine ban been puKsed over it for a long time. The crystala are like those 
formed b^' th^ action of bromine^ and ate very volatile. If stirred up with water, they 
readily dissolve ; they are very soluble in alcohol and ether, from which they crystallise, 
0» Anhyilrous conine poured upon dry chromic acidj takea fire immediately. (Hof- 
manO;^ Ann, Ch. Pharm. xlvii. 86.) 

10* Photrph&molffbdic acid (obtained by precipitating molybdate of ammonium with 
oommoD phosphate of sodium, evaporating the solution to dryness^ igniting till the 
amoioiiia is driTeu off,^ and diasolving the residue in water containing nitric acid) forms 
with eonine and its salts, a bright yeuow bulky precipitate. The precipitate is searceiy 
soluble at ordinary temperatures in water, dilute acids (with the exception of phos- 
phoric acid), alcohol, or ether ; it is however readily taken un bv the carljonates, borates, 
and phosphates of the alkalis, and decomposed, though with <lifficulty, with separation 
of ooninef by the alkaline earths and their carlx>nates, as weO as by the oxides of lead 
and silver and their carbonates. (Sonnenschoin, Ann, Vh. Pharm. cv. 4f).) 

11, Conine is rapidly attacked by bromide o/etht/K and forms a crystalline product 
(Hofmann, Ann. Ch. Phanii. Ixaiv. 175 ; hucbt. 34). Commercial conine mixes with 
1 iodide of ethyl, and forms at first a clear liquid ; but a reaction quickly takes place, 
whereby a brown oQ is formed, which sinks to the bcittom of the vessel If the mix- 
1 tufe is heated in a sealnl tube to 100° C, till the stratum of ether at the bottom no 
I longer decreases, there^ii formed, if the con be is pure, a viscid oil (hydritnlttte of ethyl- 
Loonine); but if the conine contains methyl-coninc, there is formed, besidns hydriotfbite 
lof ethyl-oonLno, the hydriodate of etbybmeihyl-conine, which solidifies in part inime- 
' diately, and com pktely on cooling, ( v, P I a n t a and K o k u I ^ . ) 

1ft. innate r/ ttA^l dissolveji conine, with evolution of heat, forming a compound 
— , the ciystallisation of which causes the mixture to solidify on cooling. (W u rt e.) 



iijri,&.^ I 



CONINE. 



SAtTSorOoNiKM. — Conine u a strong base, and D<M](Ttt]i8es adds eompktdy ; 
forming s&lfs in which 1 at. oonine ia united with 1 at. of a monobiusie Wi'\(\ 2 at. couitio 
with 1 at of A dibafiic acid^ &c These taJita may bo ob ruined in tbe fuiJid state by 
leaving their eolutionfi to OTaporate in vacuo, but tJicy are difficult to rrvBtalUse. Tbey 
dis^olre eastljr hi water, in aloohol, and in a miituiv of alcohol and ethor, but are iu- 
solnhle in pur© ether. Many of them are deliqacscent. They buvo a diaagrueable, 
bitt^ff and acrid taatet like that of tobacco. In the dij fttate tbc^y are odoarlens, but 
the aqneoYu Bolution* always amell of coninei They are decomposed by beat. 

The aqneooA solutions of conine-awilts form, with wdiite-soiuikm, a saffron-c^oloured 
precipitate, which eoon redisaolTefi. They yield flocciUent precipitates with tinctttre &f 
gaits and dickloride o/phiinum. With af kalis, they give off the peculiar odonr of 
Conine ; and when shaken vt\> with a solution of suipfutts of maffnesiunij they form a 
crystalline aalt. The solutiona, when eatj^ioBed to the air, cradually chang*?, from thi^ 
docompottitiau of the conine, acfjuiriiig a beautiful red or violet eoloiir, which jtftervv'anU 
changes to green or dark blue, and dif^appcam a^ain on addition of iiikalis ; if quitu 
neatrali tbey often become yellow or browniith. A much more rapid deeomposition 
tak*ifl place when the solution of a coninc-aalt ia eranorated by beat aud in contact 
with the air, the conine appearing to sujQeir the same alteration iuf when exposed to the 
air in the free state ; tbe solutions become brown^ and deposit brown £loeks, iiud if an 
alkali be then added, ammonia and conine are set free, and a dark-brown, bitter, m- 
^jnnoos substance ia separnt^^, which does not exert any poisonotis action. 

AjcOOTdingto Geigcr, conine-Mlts are less poisonous than the hxae itself; according 
> Christiaon*a experimeuta, on the contrary, the poisonous action of conine is ^reatlj 
ntoosified by nentraliAatioti with adds. Five grains of conine, neutralised with hydro- 
pie acid, and introduced into the Tein of a small dog, killed it in a few seconds. 
Acetate of Canine drien up^ by spontaaeoui evaporation, to a brown raniish-liko 

, which dissolves in water. 

Hydroekloraie n/ Con i n f, C*H'*N.RC1. — Hydrochloric iicid gas colours dry 

nine red and then blue. When conine is placed under the receiver of an air-pump, 

tide a vessel containing fimiing hydrochloric acid, crystals of the hydrocblorate ai'u 

in both vessels^ having the form of beautiful, colonrlesa, tranBparent lamiu;c 

[). Accordinc; to Wertheim (Ann. Ch. Pharm. c 335), conine evajjorated with 

doric acid» yields rhombic crystals from 2 to 4 millimetres long, and having a 

strong fatty liistre ; they are easily purifiod by roiirystaliisatjon from alcoboL 

bo salt disBolves easily in water, &nd becomes moist in contact with the air. If the 

llntion be left to evaporate in cohtact with the air, the salt agaijci crystallises in huninse, 

lit tams brown from decompodtion. 

Ckloroplatinate of Conim, C"H'*N.HCLPtCl^ obtained by mixing an alcoholic 

llution of Conine with dichloride of platiuum, and evaporating in vacno over oil of 

riol, is an orangery eUow cryet-alline powder^ soluble in water and in boiling alcobolf 

olnble in ether-alcohol (0 r tigos a) ; decomposed at IQO'^ G. 

itrait o/ Conine ia obtained, by spontaneoiu evaporatton, as a brown deliqni'it- 

nt mass, having the consisteace of an extracti mixed with small needles and cryatalHno 

auies. 

ilpXatB of Oonine, — Conine, saturated with dilute sulphuric acid, assumes a 

msh colour on evaporation, and leaves a thick gummy mass* with traces of crys*^ 

Ation. According to Charlord and Henry, tbe Halt ts crystallisable, deliquescent^ 

I duBoLTes in all proportions in alcohol. Potash separates the conine. If tlje eva- 

I ba carried too far, decomposition takes ^lace, and tlie odour of butyric acid 

Qes peireeptible. Sulphate of conine forms with sulphaU of alumitUuit%j a double 

\ whicn crystallises in octahedrons (conine'aium).' 

Tartrate of Coat «<;. — Tho golution, left to evaporate in the air, becomes turbid^ 
qnib^es a green and then a brown colour^ and leaves an extraet-Hke mtisa, containing 
gnmnlaz crystals. On heating the mass with water, a few brown Hakes remain 
solved. 
Conioe Conns crystaUisable salts with iodiC| ozAlic, and phosphdric acids. 

SubaHtntioii'deTivatives of Conine. 

ConiDt ia a seoemdaiy monaminei N*H-(CH'*)\ or K.H.(C*H^)V containing onljr one 

of replaceable hydrogeti r fur when it is treated with iodide of ethyl, hydnodie 

I Ikmned, and the ethyl takes the place of 1 at, hvdrogen in the base, the product 

kydriodate of ethyl^comnt (N.C^ll'.C*H**).HI ; but on treating ethylconine with 

I of ethyl, no further substitution takesnlace^ but the two bodies unite directly, 

Modetht/fatt of fthtflmnine (N»CHIC*H**}.C*H*I, or rather iodide qfdiethyi- 



6 



CONINE. 



MsTHTL-coNnf R. C"H"N-N.CHVC*H^*. — ThiB baflc is oft«n contained in com- 
ni«(reiAl cooine. It ui also prcdneod by the action of heat on ethji-raetiiyl-conine. It 
ift ft coloiirle«H oil, Bmelling like conii«.% lighter than inT4t**r^ and ipazinglj Bolnblc in 
water, impurting, howercTt a f5troijg aUudine rctaction. Iodide of ethyl con verts it into 
iodide of ethyl- raethyl-coninium. 

Etktl- CONINE. C'''H"N=N,CvH*.C*EP<. {t. Planta and Eekul^ Ann. Ch, 
Pharni. Isxjcix. 131.) — Tlie hydriodate of tMa base is obtained hy henting coainc with 
iodide of ethyl in a aealtKi tube to 100^ C, for aboat half an hour; and by diwolving 
the product in water, remoriog the excesa of iodide of ethyl by dtfcantiition^ and gently 
lieating the solution with can«tic potash, elhyl-conine eep(i«iteB> nnd may be recti£e<l 
in a cnrrent of hydrogen after being dried over fi^gmenta of chloride of calcium and 
aolid [Kfttafik 

Ethyl* Conine ia a Tolatile, almost colonrleaa, strongly reacting oil, lighter than 
water, smelling like coniuo, partiaUjr decoraposed by diatillation. Iodide of ethyl con- 
Terta it into iodide of di ethyl- oonininm. 

Ethyl-eonine ia sparingly solnble in water, but diasolres readily in acidsi, with con* 
mdtirabk ©Tolution of heat. Ita aalta do not crystalliae by evaporation. 

Tlie h^drobromate ^nA hydriodate aro un ray stalliBable, The hydrockiorate 
in obtained^ as a mass of white deliquescent cij'stala, by leaving anliydrous ethyl-conioe 
under an exhausted receiver beside a vessel containing fuming hydrochloric a^'ld. The 
chloro'auraieis precipitated aa a jeUowish oil whiek solidifies and ciyatallisea ; &om a 
bet ditute solution it aom etimes separates in beantilul yellow ciy stala. The chioromcr- 
cttraie is obtained by precipitation, as a white resinons sabetance^ which melts in the 
liquid at the boiling heat» and if dilate aolntions kk used, s^pcrates in rhomboid^] 
tablets. The ekUroplatinmit, C'*H'»N.HCLPtCl', is a yellow crystalline powder 
easily soluble in water and in alcohol, 

DiBTHTL-coNixiuM, C^'^M-'N = N.(C=H*)*.C»H'*. (v. Planta and KokuU, Ann. 
Ch. Pharm. Ljtxxix. H6.) — Known onlv in combination* The iodide, C'*H*'NI* is obJaimtl 
by the action of iodide of ethyl on ethyl-conine in the cold. This mixture, leJ^ to iti^elf 
for 12 hours, forms a crystalline mass* and on heating this product In a sealed tube to 
100'^ C, the iodide of dipthyl-coninium melts to a liquid which floats on the iodide of 
ethyL The crvstals are aofler than those of ethyl-methyl-coninium, diaaolvo easily in 
water and alcohol^ less readily in ether. 

The hydrate \9 obtain wl in solution by decomposing the ioilid© with oxide of silver. 
The HolutioD LB inodorous, bos a bitter taste,^ and strong alkaline reaction. 

The chloridet obtained by saturating the ba«e with hydrochloric acid, forms, with 
chloride of mercury t a white tlocculent precipitate, which melts when heatetl, and «epa- 
i&tssfirom the hot aolution after some time m microscopic crystals; with tricMorHU of 
fold, a sulpbur-yfillow semi-fluid precipitate which dissolves when heattd, and sieparjitea 
on cooling in oily drops wbitih become solid and crystalline ; and with dkMotidc of 
ptaiinumj on eraporation, a cryatidlino salt contuiniag C"H**N,CLPtCl*, 

Ethtl-methtl-cosinium, C'^H^^N « N.CH'.C^nM^ff*. (t. Planta and 
Kekult?', Ann. Ch, Fharm. Ixxxix. 135.) — This base also is known only in combina- 
tion. The iodide ia produced by the action of iodide of ethyl on methybconinc. 
When commercial conin©, containiJig the lattur compound (ii. h\ is treated with 
io«lide of ethyl, it yields, besides the syrupy liydriodate of ethyl -conine, cry stab of the 
iodide of ethyl-meth^l-coninium. The reaction takes place even in the cokl, sjid is 
completed in a few minutes at the heat of the water-bath. On dissolving the product 
in water, removing tho ma«a of iodide of ethyl, and adding caustic potash, a brown 
oil separates which divides into two layers, the upper, whiii^b consists of ethyl-conine, 
rema^ining liquid, while the lowor^ conaigting of iodide of t-thybmethyl-coninium, aepii- 
mtea in splendid needles, which may be pmrifiod by washing with ether containing a 
little aloohol. 

Hydrate of Ethyl-mtihyl-coninium h obtained in solution by decomposing 
the iodide with recently precipitated oxide of silver. Tho solution is colourless, 
inodoroue^ very bitter, strongly alkaline, and when concentrated acts on the skin like 
caustic potash. It abaorba carbonic iicid quickly from the air. It may be boiled 
without^ decomposition, but when concentrated and distilled, it is resolved in methyl- 
conine, wateTi and ethylene gas ; 



H 



|0 = N 



CH'.CH'^ 4 C»H* ^ H*0, 



Heated in a sealed tube with iodide of ethyl, it is converted into alcohol and io<Iid€ of 
cthybmethyl-coninittm. 



CONISTONITE — CONJUGATED COMPOUNDS. 7 

The chloride, suipkate, nitrate, carbonate, oxalate, and acetate of ethyl- 
methyl-foniniBm are cryBtaUisable, veiy soluble in water, and, for the most part, 
deliqueaeent. 

The iodide, C"H*^I, forms colourless needles rery soluble in water and in 
aleobol, insoluble in etiier and in alkaline liquids. It may be boiled with caustic potash 
without deeompoflitioa. 

Chloro-auratc, C«»H«NCLAuCl»— Plredpitated by chloride of gold from a so- 
hition of the base in hydrochloric acid, in yellow flakes which soon become ots- 
talline. I^om hot solutions, the salt is deposited in fine needles on cooling. The 
dxy salt melta below lOO*^ C. (Gk)ld, by analysis, 38*67 per cent, by calculation 38-86 
pereentk) 

Ckloro^mereurate, C*H'*NCL6HgCL —White crystalline precipitate, moderately 
■olnble in watCT, alcohol, and ether. Gives by analysis, 69*16 per cent Hg, and 
24-63 CI, the fbrmuhi requiring 69-03 Hg, and 24*46 CL When heated with water, 
it melts and dissolves, and the solution, on standing, deposits another salt containing 
C»»H»NCa.6HgCL (Analysis, 1426 per cent C, 2*70 H, and 6678 Hg; calculation. 
14*98 G, 2*60 H, and 66*76 Hg.) 

Ckloroplatinate, C»H«NCLPtCl«.— Precipitated aa a yellow crystalline powder, 
or from dilute solutions,^ gradually, in fine octahedrons. It is sparingly soluble in 
cold water, more soluble in boiling water, insoluble in alcohol and ether. (Mean of 
analyses, 36*49 per cent C, 6*64 H, and 26*43 Pt; calcuktion, 36*37 0, 6*86 H, and 
26*46 Pt) 

COWXBTO Ji XTB. A name given by R. P. Greg (Sill Am. J. xvii. 333) to a 
hydrated oxalate of calcium in crystals of the trimetric system, from Coniston in 
Cumberland; afterwards, however, found not to be a natural mineral {ibid, -g-rii 262). 

COVZTB^ or Konite, Compact dolomite. 

COVZUM IKACmbATUM. Hemlock. — This veiy poisonous plant contains the 
two alkaloids, eonine and conhydrine. It loses its activity by drying, and, according 
to MuUer, by keeping for twelve months. The extract loses its activity with equ^ 
facility, the alcoholic sooner than the aqueous extract According to Landerer, the 
green parts of the plant contain also a small quantity of an extremdy intoxicating oiL 
100 pts. of the dry leaves contain, according to Wrightson (Pharm. J. Trans, v. 40), 
6*8 pts. nitrogen, and 12*8 ash, consisting, after deduction of carbonic acid, sand, and 
charcoal, of 21*7 per cent potash, 9*6 soda, 14*9 lime, 8*3 magnesia, 2*6 siUca, 6*9 sul> 
phate of ralrinm, 16*7 phosphate of calcium, 3*6 ferric phosphate, and 16*6 chloride of 
sodium. 



COWTUVATBD OOMPOUJUJIS. Copulated compounds. Corps conjuguh ou 
eopuUs. Gepaarte Verhindungen, — ^These terms, the meaning of which has never been 
very clearly defined, were first introduced into organic chemistry by Gerhardt, in 1839. 
He had observed that certain acids, especially sulphuric add, produce, by their action on 
orj^nic bodies, pecuHar compounds in which the characteristic properties of the 
original substances are no longer perceptible ; benzoic add, for example, is converted 
bv sulphuric add into sulpho-benzoic acid, a compound in which the presence of sul- 
phuric add cannot be detected by barium-salts. This kind of union was called by 
Gerhardt copulation {aoeouplement) \ the product, a copulated compound {ail 
eopkU\ and the organic body which United with the sulphuric add, was called the 
copula {eomde, FaarUng), 

To ezplam the formation and properties of these substances, Gerhardt supposed that 
the action of snlphiiric add and similar adds on organic bodies may take place in two 
ways. Either ^e acting add loses its saturating power, in which case the product is 

formed by substitution, e,g, sidphobenzide, oq» from benzole, C"H*, by the substitu- 
tion of 8C^ fat 1 at H; or the acting add retains its saturating capacity, in which 
combination takes place by copulation. In many cases both these actions were sup- 
posed to take plaee together ; thus the formation and composition of sulpho-benzoio 

add (anhydrous) were represented by the formula ^^0* + 50". 

Similar views regarding the constitution of such acids were put forth about the same 
time by Dumas and Pina, who designated them as " conjugated acids." Berzelius 
also adopted the terms oc^mlated and conjugated, but a^^licd them in a different sense, 
namely, to designate compounds which he could not regard as formed by the union of 
elements or compound radicles in opposite electrical states ; thus water, metallic oxides, 
and the corresponding oxides of orsanic radides, were supposed to be capable of uniting 
with adds, oar electzo-negative bodies, in the ordinary way ; but the union of all other 



8 



CONJUGATED COMPOUNDS. 



bodies wm called copulAtion. Thus acelic add, C*H*€^, ms rvgardf^ as oxftHc add, 
C*C3^, copalatc-d with metbjl, C'H*; trichloracetic acid, OCP€^, aa oxalic aeid« C*0^ 
copuliated with Besqaichlonde of carbon, C^CT*. A oopdlated compound waa ddlned as 
a eompoiuid of an active subalaDce {e, g. the oxalic acid in the oompoimda just men- 
tanoe^ with a paasiTe snbatasoa or copula. Sal«titution (of O for H for AKamplc) 
was supposed to take place onl j in the latt^Tr. These views of Beneliiis hATe dearly 
no conuectioD with those previously mentioned. G^hardt in iu^ protested against 
this use at terms which he had intnxiuced in a different sense^ '^^. ^ ^^ same time^ 
defined coigugated compounds as bodies produced by the substitutioii of "ifsidiiea** 
(or compound ndicles) for ekmentary bcxlies,^ this definition indnding the amides 
compound etheiB, nitn>«ubsttttttion compounds, as well as the oompoiuids Ibniied by 
the action of sulphorie, phoephanc^ and other polyba^ie acida on hydio-^arboma and 
ofganic acids. 

In a memoir on the anilides published by I^nrent and GerhArdt in 1848^ the £>!• 
lowing definition is giTcn: — ** We designate as coiyngate compounds* ail snch as are 
formed by the direct union of two bodies, with elimination of water, and af« e^iable 
of reproducing? the original bodies by again taking up the elements otw^Xac** 

The following are examples ; 

Ethyl-sulphuric acid, formed £rom alcohol and sulphuric mad : 
C*H*0 + H»80* - C^H-SO* + UK), 

Acetic ether from alcohol and acetic add : 

Kitro-benzoic acid, firom bensoic and mtric adds : 

Cm*0» + KSC - C'H*(NO«)0» + H«0. 
Solpho-benzoie add, fifom benxoic and sulphuric adds : 

(rH*0» +H»SO* = C^fl^SO* + H*0. 
Bensamide^ &om benzoic add and ammonia: 

It is cjisy to see, however, that on this definition nearly all chemical compounds 
might be regarded as oo^jogated : for the mode of action just illustf&ted is precisely 
that which taLc^ place in the ibnnatioD of the simplest salta, 0. y. : 

Chloride of ethyl . * .(?HH> + H(a — C'H*Cl+ H*0 

Add sulphate of potassinm . * KRO + H=SO* ^ HKSO* ^ H*0 
Ghloride of potassium , . . KIIO + HCl ^ KCl ■«- H^ 

Horo recently (in his JVaiti de Ckinm Or^aniaue, I853-56) Gerhardt, while be 
admits that in a certain sense all organic compoonos ma^ be regarded as conjugated, 
nerertheless nstricts the actual use of the term to certain ^upe of bodies^ without, 
however, dlstuuctly stating what they are. He no longie? a^Jies it to the etheni, dther 
add or neutral, or to the amides ; but includes among coi\]Ugated compounds the amie 
acids, and compounds formed by the Bubstitntion of bromine, chlorine^ or nitzyl, fat 
hydrogen. The idea of a ooigu^ted compound he explains as follows : — 

** To connect together two or more systems of double decomposition of one and 
the same body, it Ls often adTsnta^eoos to represent its composition by a coi^u- 
gated mdide, that is to say^ a zadide made up of serend radiclea^ each of whit^h 
lents one such system of decomposition. We must regud as conjugated the 
i of ereiy body capable of being transformed, by certain Teiy simple reactions, 
into comoounds belonging to other radides {radieaujt C(mtiitutmtt% or in other words, 
the radicle of erery body resulting from the metunorphosis of such combinAtions. 
Thos acetyl, CHK), may be regaided as a conjugated radide composed of carbonyl, (X), 
and methyl, CH*j because acetic add and its deriTatiTes are capable of splitting 
up into compounds containing carbonyl, and others containing methyl (i. 17); imd 
couTencly, acetio add may be produced hir the acCaon of carbonic anhydride on po^ 
tassium-methyL Similarly with the radides of the other fatty adds; thus, formyl 
- CO^; propionyi = CO.C*H»; butyryl ^ CO.C*H^; amy! « CO^CJ'H', &c. The 
same acid radicles may also bo regarded as alcohol-rudiclce in which H- is ropkced W 
O ; thus acetyl, C?H*0, may be regarded as formed from ethyl, CR* ; pKjpionyt 
C*fl*0, from trityl, C»H' ; butyij-l, C^H'O, from tetiyl, C*fl»: this mode of repre* 
fM*ntation corresponding to the fact that the alcohols arc converted into fatty adds 
by oxidation.*^ 

In general, complex radides may be regarded as conjugated dther by addition or 
by substitution ; is. g. tetrethylammonium, N(C:^')\ is either a compound of N with 
4 at ethyl; or it is ammonium, NH*, in which 4 at. H are replaced by ethvl. The mode 
of repceaentation by substitution is especially apphcable to bodies formed by the action 



I 



I 



CONJUGATED COMPOUNDS. 9 

of chlorine, bromine, nitric acid, or sulphuric acid on organic bodies, and to the amides, 
amines, and ammonium- bases. 

From these considerations — for the full development of which we must refer 
to Gerhard^s TraitS (iv. 602)— it will be seen that Gerhardt ultimately gave up the 
idea of conjugated compounds as distinct from others, and retained the term merely 
for the sake of comprehending certain substances in groups, and exhibiting certain 
analogies in a clearer light His formulae, in fact, represent decompositions, the most 
important transformations being indicated by the radicles which appear in the typical 

formula : thus, when acetic acid is written, ^ 1 0, we are reminded that 1 at of 

hydrogen may be exchanged for a metal or other basylous radicle, and that 1 at 
O (outside the radicle) may be replaced by S, yielding thiacetic acid, or by 2 at CI, 
yielding chloride of acetyl and chloride of hydrogen. In these transformations the 
radicle acetyl remains unaltered, and may be regarded as a simple substance ; but any 
other transformations must affect the radicle itself, and to indicate these, the formula of 
acetyl must be resolved into others, in the manner above mentioned, the acetyl then 
appearing as a coi\jugate instead of as a simple radicle. (See CLASsmciLTiON, L 1017.) 
Considered in this light, conjugate radicles are merely modes of expression adopted 
for convenience; and it is easy to show that by the extensions of the typical mode of 
representation of chemical compounds which have come into use since the publication 
of Gerhardt's work, the use of conjugate radicles may be dispensed with altogether 
(see Ttpbs). For example, G^hardt represents the amic adds as containing radicles 
of this class, and refers them to the type HK) ; thus — 

Type. Carbamic acid. Oxamie add. 

NH.|o NH'CCOrjo NH.(CWTjo; 

but they may alio be referred to the mixed type Qjjtf • ^^ ^en the coi\jugate radicles 
may be broken up : thus — 

Tjrpe. Carbamfc acid. Oxamic acid. 

I|n M[n IfN 

Hi" n J H J 

In like manner, many sulpho-acids, supposed by Gerhardt to contain conjugate 
radicles, because they were referred to the typo IPO, may be regarded as derived from 

the mixed type 5, [and as containing simple radicles, <•.</. : 

Typca. Sulphurous acid. Methyl-sulphuroui SulphophenjUc 

acid. acid. 

g[0 CH'(SO»)jo C«H"(SO')jo 

H H CH' C«H» 

!|o T> ^'^(0 (-^lo 

The same mode of representation may be applied to the acid ethers of dibasic iicids. 
If they are referred to the type H*0, they must be supposed to contain coryugate 

radicles : 

_ Ethyl-sulphuric or Phenjrl-sulphuric or 

Type. Sulphotinic acid. SulphocarboUc acid. 

H|q C«H\SO«)0|o C-H»(SO«)0)q 

but by referring them to the type n*0«, they appear as acid salts exactly analogous to 
acid sulphate of potassium : 

Typ-. Sulphuric acid. Elhyl-iulphurlc acid. Phenyl-sulphuric acid. 

(SO')" 
H 
These examples are sufficient to show that the transformations of any compound so 
fiir as they are known, may be represented by typical formula without the assumption 








= 



C«H' 

(S07 
H 






10 



CONJUGATED COMPOUNDS. 



^ 



iwKclflfc StUI the use of ihcs^ rudid« is dtcn eonTenienii iiumniicli m 
tjrpioAl formuke of CH^mpamtivclj simple fltractoMk and siicli as biixig prcK 
* ' & certain »et of rcuetioDs, which nuLj be tlie Mipufial ol|jcct of eovi- 

Bbt it applies eqmUj veil to all classes of oompoundii eiEeepliiig of ooimo 
ana the eompoimds to which the term coij^^le hsa iwea and still 



most frequently applied^ ax« not diatingaaflbed bj anj eaaentaal 
«iiancteri from thoae which aro cammonly assunied to be of simple eomtitstioii. 

We mast not, howt^TeTf omit to notice that there are a lew eaamouid% pradoced by 
the action of sulphuric add on organic bodiee, — the vezy Hiw> mdeed, to which the 
term conjugate was originallj appH«»d, — which are ttill rappoaad, bj some ehemiatfl^ 
ti> po wpn a t pecub'ar properti«fi ea titling them to the name. 
One characteristic of a true c^oiyugated add, ia aaid to be the eompanliTaly giostpp 
mmanrn of the compound radido which it contatna* and tha power pooaeeeed by 
i ladiele of passing tnim one type to another without deeompoaitioo. Thua, solpho- 
f hwj lie aeid is transibniied by pcntachloride of phoqihoraa into chlocida ef snlpho^ 
flMoyl, and this, by the action of ammonia, into sdfbofhcojiamide : 

BolplMiihenjIle Chloride of ampbnelwyiU 

Mod. iiilpliopbtiajL a iM«. 

C-H-CSOpjo c-mSO'lCl *^T|k 

Hare the radiele CIP^SO*), which ia found in idl the three compounds, is aaid 
conjugated* The formation of the chle'inde &om the add may, howeret; be aho" 
take place quite in the itHual wuy^ without assuming any peenhar fixity ui this 
The action of chloride of phoephoms on adds and other oxides is known to 




the replacement of 0, in the type H*0, by Cl'» the reemlt being the formation of two 
epanite chlorides, becuuse the bond which held together the two atoms of hydrogen, 



or their equivalents in the type H'O, is broken up : thus. 



H[^ . Ha 

hJO givea g^; 



C*H»0 
H 



i° 



giTea 



HCl • 



In like mimner, if we represent snlphophenylie add by a formula modelled on the 
mixed type ttj [,we find that 

SulphciphaojUc Chloride of 

aclid. lUlpbopbPDfL 

cm* c»H* 

The chloride belongs to the tainted typo 5^1 1* *^^ ^'"^ molecules H* and HCl being 

held together by the radide ^0', jnst as the two tnolecnlca H^ and H^ were in the 
original add. 

In fact, chloride of snlphophenyl is related tn snlphopbenylic add in exactly the 
same manner as chlorbydroeulphnric add (SO^HCI)^ the compound formed by the 
action of pentochlorido of phosphorus on sulphuric add* ia related to that add : 



Tnw- 



l\o 



ill 



21° 



Sutphurlc 

(SOT 

H r> 



TjK, 

H 

JH 

ma 



Cblorlifdro- 
ialpbinic 



(SO^ 



? 



^JT^* pbenyUeacliI, 



n 






(SO*)^ 
H 



!» 



Type* 
K 



Chloride of 
■alphoplienjrL 

(SO«)'',Gl 



If snlphopbenylic odd is to be regarded as conjugated, on account of tiie formation 
of chlondo of Bulphophenrli sulphuric acid ought likewise to be regarded aa a coiyu- 
^Led add, on account of the formation of chlorhydrofulpharic add : 

Sulphurk acid. Sulphopbenyllc meldt 

Odorhydroealphanc add would then be regarded as the chlonde of the some radicle, 
namely, H(S0^0.C1 ; in fact, when treated with water, it reproduct»s enlphuric add, 
just aa diloride of solphophenyl reproduces sulphophenjlic acid. ( K e k u 1 <&.) 

Another class of adds to which the term conjugate is stiU sometimes applied^ in- 
cludea those whidi resolt from a pecuUjir action of sulphuric add, espedally of the 
fuming add, on certain organic bodieft, — the change consisting in the abstracliou of an 
iktom of hydrogen from the radicle of the oompoondr which radide accordingly under^ 
goea an attemdon of atomidty, becoming, far example, diatomic instead of monatomic 



I 



4 

I 



d 




CONNECTIVE TISSUE. 



II 



Thm chanf^e may, hawover, be easily represonted by tneatis of mixed tjpes, as in the 
following fonuuJiG cf sulphacetlc iluJ Biilphobeaxoic acids : 



HI" 



Acuik" acid, 
Sulphacotlc Add. 

(so>)"S 



nenxoUr acid, 
StilphobcDxolc acid. 






O 



These siilpho- acids are fonnod from acpdc and benzoic acid in th<5 eamo manaer as 
(Cm*) »q C'H*) 

1 acid, (SO*)" { , from alcohol, „ [ 0,. Now this last acid may be formed 
H* Jo ^> * 

(CTITlo 
the action of boiling water on lulpbate of cirbyl, C*H*SK)^ or (SO*)"! , which is 

(80')") O 
t'lf a product of the action of snlphtiric anhydride npon ethylene CH** In this laat 
'n of fbirmation there in no alteration of the radide ; consoquentlj^ if sueh altenitioD 
I flttpposed to necessitate the representation of the resulting compouad by a formula 

atauung a conjugate ladide^ e, g. sulpbaeetic acid, by ^ ^i) 0,iuidisethionic 

ad, by ^ Tf [ O, it woold follow that th*? Last-mentioned acid might be regarded 

I corrugated or noa-co&jugated, according as it waa formed from alcohol or from 
Bttlefiant giu. 

Fium all theee consideratioDs it follows that there is qo case in which the use of 

on jugate radicles is a matter of necessity, the use of a radicle or of a type of greater 

r few oomplexity being in all cases a matter of convenience, and dfttermiued by the 

^particDlar kind of chemical tnunformation which the formula is intended to represent. 

It would be well, therefoire, if the idea of cor^j ligation, as denoting any peculiar mode 

of chemieal oombinationf were altogether banished from the edence (Kekul^ 

LtMuck ier Orffamschen Cherme^ 1859» i lfl2).^0n the history of conjugiite com* 

, see also Limpricht and v. Ualar, Ann* Clu Pharm, cii. 139; Mendias, 

' 89;Kekul6, ihid. cij. 129; cvi, 129 j Limpricht, Md. dv. 177); also 

I Cu^ssimckTioN^ Radwulb, SuBSTrrtrrioN, and Ttpes, in this Dictionary. 

TiB&lflS. BiitdfjfefDfbc,— This term is applied to a tissue 

hemically allied to rartilsjge, though of a simpler character, and oompriaes, not 

terely the porons solt cellular eubetance, characterised by the readiness with which 

may be filled with air, which eonneets together the Tarions oi^ns und tissues of 

I aoimml organiBm, and was fbrmerly called o^tdar HMue^ btti also those morpho- 

EicaA elAments which constitute the solid basis of many of the animal membranes 

liinenta. Th^ tissue which connects the organs one with anoth<»r, forming a 

: of variously sized meshes composed of long e lender fibres (of 0i>003^0*0006"* 

er), for the most part united iu bundles, is ctillpd am/frphous (Henle), or ioote, 

^ ooimtctive tissut (K o Hike r). This tissue gradually passes into a more solid 

r dbtineiiiBhed by t he e pi thet formed (Henle), or compact ( K o 1 1 i k e r] , which 

I the ba«s of the tendons and ligaments, the fibrous membranes and muscular 

Bi the envelopes of many soft, ni^ans (the dura mntfr, nfttroUmma, &c.), the serous 

I synorial membranes, the coats of the veins, the soH?alled vascular membranes, {pia 

atrr, cAoroHdmt Stc), the interarticular cartilagea* &c. 

The true connective tissue is, however, constantly mixed with vcasels, nerves, fut-celK 

* r fibres, and frequently also with unstriped muflcular fibres, which cannot be 

lljr separated from it, so that its chemical examination is a matter of some 

Htj ; but &om the analysis of those organs, such aa the tendons, in which it is 

red with the smallest amount of these morpbolagical elements, it appears to be 

entical in eompoeition with gelatin. 

Connective tissue immersed in boiling itntter contracts eoroowhat at. fir^, but soon 
rella np like a jelly, and dissolves on prolonged boiling, yielding a solution of gelatin, 
r the water contains an acid or alkali in solution^ the trans formallon is eflFected mudi 
ore quickly. 

The change which here takes place is rather physical than ehemical r for the con- 
nective,^ And indeed all the gt lutinising tissues, appear to htiVQ essentially the same 
litioa aa gelatin itstdf, as may be seen from the following analyses by Scheie r 




12 



CON NELLITE.— CONTACT ACTION, 





Scberffr. 




Mulder. 










IfinilKM. 


Tendrai, 


Si:lerotica. 


StAg'* ht>rD> tiiD^taci 


50567 


50774 49-563 


50'996 


6006 60-76 


6 903 


7 '152 7-148 


7075 


6-64 6-64 


18790 


18 230 18-470 


18-723 


18-39 18-31 


23-570 


23754 24-81 & 


23-207 


24-92 24-29 



(Ann, Ch, Phann. bt. 46-49) and MuMer ( Vers, einer (dlgem. phi/mol. Chem. Sraun- 
stvbweig, 1844—61, p. 333.) 



Carbon . , 

Hydrogen » 

NitnigeD . 

Oitjgcn . * 

In concentrated aeetic acid connective tissme swells op and becomia transparent, bnt 
doos not dissolve till WAter is udded and heat upplied. The ac<?tic solution is not pr«- 
cipitated either by red or by yellow pmssinte. In dilute acetic acid» the fibres of 
connective tisano likewise swell up, becoming trunsparenfc and inTiaible, but do uot 
dissolve, evfu after several hours' boiling ; for on washing with pure water, or neuttid- 
itttBg the acid with ammonia, thoj reappear in their original fonn. As most of tho 
other textnral elements which are intermixed with the connective tiKsue are not 
rendered invisible by acetic acid, they are brought more distinctly into view by its 
application : hunce this acid affords valuable iiid in the histcdo^eal study of tho tii^aiiea. 
In alkalis the tlbroa also swell up in the gehitinoua form, hut if the action of the aOciili 
has been continued for some time, they do not reappear on addition of water^ but are 
thnrrby dissolved. 

EmbrjonicconnectivG tissue (Virchow's inucom tisau4>) does not yield Rclatiii 
when boiled with water, (Seherer); it ei>nsii^t5, in addition to fiisiform cells, of a 
peculiar intereelluhir substance, which, when digested with water, yiehis albumin 
together with a gelatinous ormacotis fiubfitonce. {Lehmann's Ph^tioioffical Chemistry^ 
iii. 46 ; Gnhttm*^ HandbucK viiL [2] 457). 

COnVEUUnib A Cornish mineral, coniiatiiig of coprio ehloridep «nlphato, and 
water, foraiing small fibrous ctyet^, belonging to the hexagonal systeia, translucent, 
of blue colour and ghissy lustre, insoluble in wat«ipj easily solnblo in hydrocldoric and 
nitrio acid«. (Ooiinell, J* pn Chem. xliL 453.) 

COWT&CT AITTZOW. Catah/tii.^ action, Catali/sis. These terms are applied to 
a numerous class of chemical actions, in which the combination of two Ijodies, or the 
«lecom[Kjsitiou of a compound^ is brought about by tho intervention of a fiubstance 
which shows no tendency to unile with either of the bodies concerned, and renudna 
unaffected by the ehiinges which take phice. Bcrzelius, who flj^t drew attention lo 
this class of actions, supposed that Bub«t!iQCPS acting in this manner possessed a pocu- 
bar power which he called '* catalytic force " (from KaraXmuf^ to reaolve); ho 
regarded this power as a manifeBtatiou of electric force^ diflferent, however, from the 
ordinary action of electricity. Mitscherlich designates subBtances thus acting **con* 
tact Bub stances," and the mode of action, as chemical action or combination by 
contact. 

Examples of these contact actions are found both in inoiganic and in organic 
chemistry; e. t/, the action of platinum and other metsils in inducing the combination 
of oxygen and hydrogen ; the rapid decomposition of peroxide of hydrogen by the 
presence of platinum, silver, fibrin, &e. ; the conversion of starch into dextrin and 
sugar by boiling with acidulated water; the conversion of cane-sugar into gnipe-sugar 
by contact with acids ; and the numerous and varied phenomena of fermentation sjid 
putrefaction, 

Tho eooiiection between these somewhat obsenro phenomena and those of ordinary 
chemical action, is perhaps to be found in the idea suggested hy Benselius, that they 
axe due to »ome modification of the eJectric state of tho bodies, or, to spenk more 
generally, to a pohmftatiorf of the combining or separating atoms induced by the pr*'- 
sencii of the apparently inactive body. Take, for eitimple, the action of platinum in 
inducing the combination of oxygen and hydrogen. Wo know from the effi^ets of 
Grove's Ka^-battery (aeo ELEGTmcnr), that when two glass tubes containing oxygen 
and hydrc^cn re^pc-ctively are inverted over witter, and platinum plates immersed in 
them, partly io the gas and partly in the water, tho plates being also connected by a 
wire outside the tubes^ the gases gradually disappear, and a voltaic circuit is formed, 
in which the platinum immersed in the hydrogen eorresponda to the positive or zinc 
tolate of the ordinary batter)^ This effect indicates a nolarisation of the molecules of 
hydrogen, oxygen, and platinum, such as is represented in the following diagram ; 

R H Ft 

- + - + 

Now it is highly probable that a similar polarisation and consequent combination of 
the ox^en ana hydrogen takes place when a clean platinum plate or wire, or finely 
dividod phitinnm, is introduced into a mixture of those g&ses, the eflfect of the metal 




CONVALLAMARETIN^COKVALLAMARIN. 13 

being due to the fucilitf witli whieh its contiguous particles plaeo tliempelrra in oppo- 
site electrical or polar stut^is. Tho peculiar efficacy of platinum in bringing about such 
rombiiiationa, appears to be related to its medimn position in the plfictrical or chemical 
Belies ! w« know, indeed, from the purt^ly dieinioal relations of platinum, that it i« 
almost eqoallj disposed to play tho part either of a chlorous or iicid, or of a po«itiTO 
or httsylous element. The more eseigetic action of the finely-divided metal \b of course 
flue to it« larger surface, &nd to the power which such bodies post^ess of coodeusing 
giifips within their poresL The deoompontioii of peroxide of hydrogen^ by contact with 
platinum and other metal^ may be supposed to t4ike place in a ^milar manner. 

The polarised state to which we hare attributed the action of platinum in thesfl 
coses is by no means an isolated con^lition, but one which perradea the whole range of 
chemical phenomeina. That the whole of the molecules comixising a Toltaic circuit 
may be regaided as polarised, was pointed out many years ago by Grab am {EUmmfs 
^J Chemigtry^ Ist ed^ 1841) ; ana that a similar pohm&ed state comes into play 
In ordinary cases of chemical action, and may serre to ac'count for many phenomena 
Usually regarded as pomewhat obscure, — Buch iia the peculiar energy of tM>dies in the 
fio-calicd nascent Btat<*, — the decomposition of peroxide of hydrogen by certain metalH<i 
oxides, which are themselTCs at the same time reduced to a lower bIoXq of oxidation — the 

+ — + — -^ ^ — ♦ 
reaction between hydrochloric acid and hydride of copper (Cu'H + HCl = Cu*Cl + HH) — 
the mutual decompoaition of hydriodic and iodic acids^ — and many similar phenomena, 
^- was shown by Brodie in bis paper *^ On the condition of certain elements at the 
moment of chemical charge " (Phil. Trans. 1850, p. 759) ; see also Chkkicai* ArrmiTY 
(}. 858). When, therefore, we refer the action of platinuin and other metals to chemical 
or electrical polarity, we merely point out that these phenomena may be regarded ai* 
particular cases of a recognised mode of action. Whether the so-called contact actions 
which are so freqnently observed in organic chemistry, such as the action of ferments, 
and the conTcrsion ot starch into sugar by the action of acids, can be explaiuc<l iu a 
similar mannerf is a question which does not at present admit of a decided answer. 
(See a paper by Dr. T. L. Phipson : La Force catal^ftique ou Uudcs aur ks Phhio- 
Mhtu de CmiacC Haarlem, 18S8.) 

It not uiifreqoicntly happens that reactions uro effi^ted with case by using a con- 
tidRmble excess of one of the reagents, which can be brought about only -ft^ith difficulty, 
or not at alL by using only as much of the reagent in question as actually takes part 
in the chemical change. These reactions may reasonably be regarded as a special 
rl»»s of contact actionis tho excess of the reagent facilitating tho action of that portion 
which takes part in the reaction^ in much the same way ss in other cases, the •* conUu^U 
auhnimtc*''* promotes the action of a body cbemicAUy different from itself. Thti most 
probable explanation that has hitherto been sji^ipeHted of this action of (hf ma«4 of 
m reagent, and of catalytic actions in general, is that the eontaet-suljst^mce ai<sists the 
reaction, by exerting its affinity in the same direction as the bodies stnTing to rewet 
mptm another, but under such conditions that it cannot itself undergo alteration. This 
1 mode of action will bo made more easiJy intelligible by an example : if oxalic 
[ is heated with nitric acid until it begins to he oxidised, and water is then added 
V Bubctnre until the action ceases, the oxidation immediately begins again on thu 
I of a small quantify of a protosalt of mojijianese (]il ercer). In this int*tiTince, 
f tiha tetkdencj of the manganous salt to become a manganic salt, acts in the same direction 
^ as the attraction of tho elements of the oxalic acid for the oxygen of tlie nitric acid, 
rhich is thna decomposed under the influence of both substances acting together, under 
I eircumatatieea in which it would not have been decom]x>i!ied by either alone ; a scaquj- 
salt <Kf mttlig^eae being, however, incapable of existing in an acid stjlution containing 
^ He arid, the protopalt of manganese remains unchanged, although aiding by ita 
nee to bring about the reaction. This mode of explaining many cases of tto-called 
l.Qifx!QntacV was Hret suggested by Mercer (Brit. Assoc. Rep. 1842, Vi^h ix. Notices 
Picts, p. 32); it was further devi loped by PI ay fair (Mem. and Proc. Chem. 
Jf) iii 348), and is applied by K e k ii U (Lehrb, d. Org. Chcm. i. 142. note) to 
ation not only of such phenotnena, but, in the way indicated aboTc, to 
only referred to the action ef mats. 

XTift W ^W''**"'- A substance produced by the action of acids and 
{ilkalis on convalianiarin. It separates from the liquid iu dTStaMine ^langlea, calcM 
her intn n resinous mass ^n Ixjiling, molts when heated olone^ and decomposes by 
' distilktion. (Wala.) 

O^yyv/ML^AfltAHi^^*- A bitter substauce contained, t4>gethcr with conTallarin, 

: in i\>nvaUi\rUi ihnj^tH.-i (Solomon's s^alK It is obtainiHl by diluting and filtering thtj 

Tni»tlief-liquor fn>m which the convalhirin hoi* sojiarutcil, tlien (hgc^ting with *"»i"^^ 

rliareoal, precipitating with tannic odd, and separating the tannic acid withojtidoof lead 



IftddttioiK 



14 



CONVALLAKETm— CONVOLVULIC ACID. 



ConvaHnmarin « & white powder, bsving a bitter taate, with peculiar swcetisti i 

Bie, eaiiilx soluble in wat«!r and alcohol, neiirlj insoluble in etlier. Bjr hetttang tJi* ' 

ftqaeons ttolutioti with dOate sulphuric acid^ the conTallamarin is resolTed into fugar; 

water, and convallamaretin* Nitric acid colours con vail amariQ ydlow ; strong Bulphorie 

ucid colouTB it Tiolet, but the colour disiMiean on dilution. Alkalis decompoeet it, 

with aepuration of coQTuUatnaretin. (Wafs.) 

OO WA.ZiXiASXTXV« 6ce OoNYAUASrif* 



C Oinr/i TiTi ft "PT A ■ Tbo flowers of Cfmvaliaria fnqfalu (Solomon's seal) jityld, 
by dbtiMiitioo with water, a small quantity of a rolatile, cryataUiae, stroog-emelling 
ttunphoroidul substance, and a bitter principle (Herberger). Wala (N. JohrU 
PhiLnzi. 18d8f X. 14o) hoa obtained from thu plant two compounda, naoHsd cou- 
vallarin and convallaniarin. 

In the herb and stalks of lily of the vall<^y, CanvaUaria muUifiorfL, Wa]« fitubt 
aiptLni|;in, starcli^ sugar, citric acid, malic acid| and a cryfltaliisable aubslanco which 
produces a Keratdiing si^Dsation in the tbroat, 

frftlfV A JmTi ft BTTT ■ A substanco contaiQCMl in Convallaria mtffatis, Th^ plant, 
collected during op after the flowering time, is dried, piilvcriaed, and exhausted with 
alcohol of 0-84 ; tlw tincture is precipitated with subacetatc of lead; the k^nd removed 
from the filtrate by sulphuretted hydrogen; and the cryatala of convallarin, which 
scpjirnto on evaporationn are purified by washing with ether. 

ConTidJarui is composed, according to Walz, of C**H^O^^; it crystalliseB in right 
rectangular prisma, is sparingly soluble in water, to whit^h it imparts an irritating 
taste, mid the property of fejthing when agitated. By prolonged boiling with ueidw, it 
is said to yield BUgar andconvallaretin, C^H* 0", a y ello wish -white ciy stalline ma8% 
soluble in ethcTi and haring a sligbt ri^inous taste. 

GOWOK17UKIC A^CIII. An acid formed from conTolTulin, uiid«^r ih^ inAuenca 
of bnscft, by nddition of tJio clementa of water. It was first obtained by Kaiser (Ann. 
CIl Pharnu li. 30), who culled ithydro-rhodcoretin, and assigned to it the formula 
C^'IP'O^^ afterwards more fully examined by Mayer {ibid, Lxixiii 126 : xcv. 162X who 
gave it the name rhodeo relic acid^ and regarded it as a dibasic acid, C**H**0'MI\ 
or €^1^*0^*2110 ; subsequently, however^ he has considered it as a tri basic acid^ 
with the formula C*H^O^.^Hd (or sexbasic, according to the formula C*^H"»0**.H*> 

ConTohidic acid is prepared by boiling 100 grammes of convolvulin in 500 gmie, of 
liaryta-wftter with frequent agitation ; precipitating the bajyta, i^ftejr cotdinp, with a 
fili^iit excess of sulphuric acid; then remoring the excess of sulphuric acid by ogitation 
with carb3uate of lead ; precipitating the dissolved lead by snlphuretted hydrogen, 
and evapomting the filtrate on the water-bath. 

Convolvulic acid is a white, Tcry hygrometric substanccv pesemhliog conrolrulin in 
appearance, soluble in all proportions in water and in alcohol^ insoluble in ether, The 
aciucouH solution has a strong acid reaction, nnd a very faint odour like that of quinces. 
It sofl^na at a few degrees above 100^ C, melts between 100° nnd 120^, and dfioompoaaa 
at higher tempt£rat4irti». 

It contains^ aooprditig to tba mean of Mayei^B analyaw, 52*60 per cent, carbon and 
7 81 hyflrogen, wbenco Mayer deduces the formula (?'B**0^ (5 2' 8 per cent* G, and 7*6 O), 
representing the acid as couTolvulin, pfus 8 at. water. This formula is, howcTer, im- 
probable, on aeccmut of the uneven numbers of atoms of liydrogen and oxygen. 

OjijvoIvuIjc acid reacts like convolndin with acetic, nitric, and strong sulphuric acid. 
By Ijtiiling with dilute sulphuric or hydrochloric ucid, it in resolved into convolvnlinoUc 
acid and glucose ; the same effect is produced by cinulain : 

ConTolvuVic acid expels carbonic acid from olkulinc and earthy capbonnfes, cjipedally 
with the aid of htaX. The aqueoiufi solution of the acid, eitbeir frta or after neutralis- 
ation with ammonin, does not precipitate the solution of any neutral metallic «alt ; but 
with basic acetate of lead* it yields whit« balky flakes. 

The acid, boiled with excess of haryta-watfr, yielda a no-called neutral salt, 
O^Ii^^Ba^V^i?}, while if the add in in excess^ an acid salt, O^ff^BaCP^ (?), is obtained. 
Botli salts arc amorphous, diaphanous, brittle, bittej, with an odonr of quinces, Tery 
soluble in water and aleohot melt between 100^^ and 110^ C. A caieimn-MUt 
C^H^^C€^(^ i?\ obtained by boiling the acid with milk of lime, is amorphoua; 
elightly yellowish : its aqueous solution has a faint odour of quinces. 

An ttad jtotagjsivm-salt, containing 5 05 percent, pcvtash, is obtjuned by saturating the 
acid with |.KiLaith, evaporating to drync*H and rcdisiwDlving in alcohol. It i»amorphouA, 
Tery soluble in water, sparingly in alcoliol. The aqueoua aolution i,H bitter, and has the 
odour of quinces. Thici salt mel is between 1 OQ^ and 110^ C. (M ay er. ) 



CON\^OLTDLIK— CONVOLYITLINOLIC ACID. 



15 



OOWOlWXXir. A reain contained in the tubeitwe or officinal jalap-root (the 
ilbome of Cont*ohntlu^ Suhndunu^, Z ticc). According to Maj cr' s luMt inrcstigiitioiia 
kAnn. Ck Phunn, xcj. 161), it contiiins C""H*"0'* or CB^O»», md is homologoua 
ith jalapin, th« resin of fusiform jaJap {Cf/nwtvidus oH^abenms^ Pell)* [It may 
» inferred from Mayer's eiperimenta, tliough the fact is not distinctly atated, that oon- 
Dimiiji and jalapin exist togttber in both kinds of jalap-root, the convolnilin being 
ore abimdant in the tuberoae, the latter in the fnaiform Bpecics.] Mayer formerly 
aed it as C^B^O** + BO; Kayaer (Zo<f. dt) as C**B^O^; Latirent as C^B'^CP*, 

ConyolToHii ii prepared from the root of Contjoltntiut ScAiedan tu by eixbaiiating the 
ot with boiling water ; drying, and coarsw'ly pulverising it ; then treating? it three 
^witb twice ita weight of aJcobol of 9U per cent. ; mixing the alcoholic extniet 
' tin it hegJM to show turbidity ; then treating the liquid tv^iee with animal 
distilling the alcohol from the filtrate ; repeatedly treating the rmdual pul- 
sein (amonntingto between ID and 15 per cent of the root) with ether; dia- 
J the residue in the smallest potiHible quotitity of absolute alcohol ; preeipitating 
ith ether; and repeating the solution and precipitation till the precipitate w qiute 
\ from the portion of £e crude resin whicE is soluble in ether. The residue ulti- 
tely obtained is pore eoiiTolrulirL 
ConTolmlin is a coloorless transparent reain, wbicb, when pulTerised, yields a white 
' like gum arabie. It is tasteless and inodorona, nearly ini»uluble in water, 
soluble in alcohol, but indoluble in ether* whereby it is diatinguished from 

rtn; the alcoholic solution bas a slight acid reaction* The resin melts below 
C. when moist ; but in the dry state it softens only at 14 P, and tmylts at 150° 
a light yellow transparent liquid; aboTC 165"^ it begins to decompose. When 
ed in the air on platinum foil, it bums with a. smoky flame, diflusiug un odour like 
i of carameL 
CbsTolrulin, dried at ISO^ C, contaiiLa» acoording to Mayer's analysis, fVom fil'21 to 
pfi'Ol per cent carbon, and 7 '89 to 8*07 hydrogen ; the formda, C«H*«0", requires 
^ 1*97 C and 7 37 H. 
Finely divided conTolvuKn dissolves in aqneous alkalis even in the cold, more 
laily when heated, and is converted into convolvulie acid It dissolves also in aeetic 
cid. Very dilute nitric acid dissolvea it slowly in the cold, more rciidily when healed, 
at with decomposition. Stronger nitric acid decomposes it immediately* with evolution 
r nitrous acid and formation of oxalic acid and ipomeeic acid, an isomer of sebacio 

(C"H"0*). 
Coovolvuiin dissolved in alcohol is resolved by hydrachloiic acid into oonTolTulinoHc 

2C?«'H«0'* + 11H*0 = C"H*«0^ + 6C«H«0*, 
CoovoJruUn. Gootolrulln(»lic Gtacoio. 

acid. 

DTolTniin is not affected by cold ddnte sulphuric acid ; bnt, when triturated with 
ong sulphuric acid, it diBsolTee with fine caimine-red colour^ changing after a while to 
the soltition after standing for a longt^r time deposits a brown-black subatanee. 
I this reaction also, oonTolvylin is resolved into convolvulinol and gLucose. It is 
beie^Kre a gldcoeide. 

Gonvolvtinn is the active principle of jalap-reain ; it exerts a rery strong piirgft- 
ive action, even in doses of a few grains. 

COWO&Vin«070&XC ACZD. Convoiimlmoij Bhodeoretinof. (Kaiser, loc, 
i7. — Mayer, he. cit.) — This compound is produced, together with glucc^c, by th»j 
Paictioo of dihiito adds, or of emulsin, on convolviilic add. To prepare it, 30 f^rms. of 
{eonvolvulie acid are dissolved in 300 grms. of water^ the solatiou is heated to the 
I boiling paint, and 20 grms. of strong ^phuric acid diluted with 200 grms, of water 
fiftre added to it, the boiling being continued for some time, Convolvulinolic acid then 
ipartly sepaiutes as an oil, partly remains dissolved in the water, and separates in 
lo>1oiuicas microscopic needles on cooling. It is inodorous, but has a harsh, slightly 
I tiitter taste. It dissolves but verj- sparingly in pure water, more freely in acidulated 
very easily in alcohol, less easily in ether ; it does not crystalliso either fnini 
bol or from ether. It feels grt»asy and softens between the lingers, melts at 38 fi® 
^ C. to a yellow oily liquid, and solidities ag;dn nt ^i\^. The melted acid, difihsed 
I water, imparta to it a peculiar oiioiir like that of the earob bean. 

[Xvd on platinum foil in contact with the air, it appears to volatilise for the most 
^thoal decompc^ition, the vafX>ur8 having a strong eougli-exciting odour like 
! aelitiicic acid. Strong sulphuric acid ccdours convolvulinol, tirit yellowish, then 
nth-red, like eon vol vulin. Strong nitricacid oxidises it to oxalic and ipomteie acids, 
DTolvtdinolic add, prepared as above, contains, according to the mean of Mayer's 



W CONVOLVULACE^— COPAIBA OIL. 

anuIyBOS, 65 47 per cent carbon mid 10*71 hydrogen, wLcnco he deduces the improbiil>le 
foramlii C^M^O^ (66 8 per cent, C, and H)'5 HJ. Wlien st'panited from itssultj!, how- 
GTcr, it ha#, iiccording \o Mayer, tlio compoeition C^lP^if'. A product LaTiny; tliis 
oomposition is iikewLw obtainod by heuting convolruHn or coiivolvulie ucid with hydrati' 
of sodium and a little wntcr, as long aa hydrogen continues to escape^ dceompogiiig tJie 
aqueous solution of the product with aulphurie acid, and purifying by solution in al- 
cohol^ and treatment with animal chiirooaL It resembles the pi^ceding in all its pro- 
porties, excepting that it melts at a somewhat iiigher temp^^raturc (40'^-— 45*^ C), and 
haa a etronger acid reaction, 

Mayer applies the term convolTulinol to the product of the action of acids on 
conTolTuHe acid^ and designates as coutoItu lino lie acid the compound aepftpated 
frorai the conTolrulinolatpfi, or obtained by the process lust d^cribed; but it is moflt 
probable that the two suhstoneea ane merely the same acid in different atati» of bjrdn* 
tion. All theie products require re-eiamination. 

Tho convolTulinolatea are composed, according to Mayer, of C^H^^MO^^ or 
MO.C^IP^O*. Tihose of the iilkali'metak are easily soluble in water and in alcobol, 
and are obtained by treating the alcoholic eolution of tho acid with caustic alknlift. 
Thoae of the aUialine-earth metala are sparingly soluble, and are obtained in like 
manner. Tho«e of most of tho boaTy metalji are mioluble and are obtoioed by preci- 
pitation. Tho lead-salt is said to contain C^Ii'^PbO^. (Mayer.) 

COIfVO^'VTT^A.CKS. An order of plants yielding many useful products* The 
roots of sevt^ral Hpecies of Omvolmdus and Ipotntea yield purgative renins, or gnm-reaius. 
ConvohvdtfS scamnumiumy L., yields scammony (g. ».), (Z Schiedanits and C. onsn- 
bcmis, or Ijfoma^a oruahnmi^ yield jsilap, C.turpethum^ or L turpeihitm, also yields 
a purgatiTtt resiiL C baiutas^ or Batdlas tduHi^ the Spanish potato, yields edible 
ttibflire, w»embliag the common potato, but of sweeter t^sl^ {i. 620), C tcoporius^ L., 
and C, ^ridus, L*, ^'ield one of the woods called rose-wood, 

OOVTSSXWS. See Coxutdrcnb (p. 1). 

^^^ « «^^* «.«*« C Sec Copaiba Oii^ 

C03PAH1JVI0 or CQPAZVlC A.t3l]|i See Copaiba Restns. 

COPiLZBA BAliSABC. See Bai^ams (L 492). 

caPAZSa^ <lZXh Essence de Cmmhu. (Bonastro [1&25], J. Pharm. xi. 629. — 
Adi>r, J* Pharm. xv. &5. — Gerbert Br. Arch. xxs. l67.^Blanchet, Ann. Ch, PhamL 
Tii. 166,^8oubeiraa and Capitatm?, J. Phiinn. xxvi 7<X— Gni. xiv. 2H6,)— The 
volatde oil contained id balsam of copaiba. It belongs to the catnphenes, C'**H", nr 
C^W*. Copaiba balsam is & mixture of this oil with resins, the proportion of the oil 
Tarying from 30 to 60 per cent, in balsams from diSerent localitiea. 

The oil is obtained by distilling the balsam with water, and may b« purified by 
drying over chloride of calcium and rectifying. To obtain the whole of the oil, the 
diatillatiou with water must be repeated six or eight times (i;?onbeinin and 
Capitaine). According to Ader, th<3 oil may be separated b^^ agitjiting \m pt». nf 
tho balsam with an equal qmmtity of alcohol of specilic gravity 836, then adding 
37 J pts. of soda-ley of ap<»ctfic gravity 133, and diluting tiie whole with 150 pt«. of 
water. The oQ then gradually risea to the surface. 

Pure oil of copaibti is tmnsparent, colourless^ or yellowish-green, mobile, and has an 
aromatic odour like that of the balsam ; that obtained by Ader*fl mHhod is tut id to 
have a more disagreeable odotir ; the tjiste is sharp and persistently bktcr. 8pecific 
pravity 0"8B1 — 91, increasing to 096 on exposure to iho^ air, Boiliug-|X'tiit 245*^ — 
2G0° C. Optical rotatory power = 34" 18^ to the lelL Expansion from 0^ to lOO** C, 
= 0083132; from 100^ to 200^ = 0104034 (Aubergier, J. Pharm. xvii, 278). 
The oil is nvutral. It solidifies, partly crystalline, at — 26° C. Oil of copaiba cli?*sf>lvi'M 
in 2-| ptfl. of absolute ako/toi, and in 26— SO pta. of alcohol of specific gra^-ity 0'8o, 
(Aceortling to Stoltze, it dissolves in all ^iropcjrtiona in alcohol of this strength.) With 
ifu/phtdr of carbon and anhydrous ithir, it mixf's in all pro[X)rt^ous, but not with more 
thaii half its weight of common ether. It dissolvea sulphur and p/t(fsphorua with aid 
of heat It likemiiie dissolves glacial acetic acid and h^dtDci/anic acid, and mixes with 
alcoholic succinic and bentoic acids ; also with solution of oxalic acid, but not with 
ciirtc acid- It absorbs ammonia^ becoming milk-white amf liscid. (Gerber.) 

Copaiba oil becomes brown and viscid by continued boiling. Chhrint in ancshine 
makes it hot, colours it yellowish blue^ and then grt^ n, and »enarates white crystal line 
masses (Blanche t). lodinf, slowly added to the oil, distiofrri* without detonation 
(B 1 ft n ch c t). funning a red difih-yellow» or brown-black liquid ; if it be added morequickly, 
heating and frothing take place, and a brown muss is formed (Gerber). It detonatt^ 
with/wwii«^ nitric acid^ leaving a brown r©«n. With nitric acid of specific gravity 



COPAIBA OIL. 17 

1-32, it resinises only when heatol (Blsnchet). Ac(?ording to Boniwtw. it aBanmea 
ii violet tint at the beginuing of the action. Weaker nitric aeid fonna with the 
oil ^smsU quiuititj of yellow resin, precipitable hy water (Gerber). Oil of titrud 
nuikeB il hot ami ttmiB it red- brown (Stoltsse). ^Ith a few dru|w of oil of Titriol 
it becomes hot and bkcker ; but whon droppwl into a Inrger quantity of oil of vitriol, 
it forms a red-brown Boiiition of iulphoterebic acid- (Oorhardt, Compt rend xrii, 
31i.) 

With htfdrochiiiric acid, {M^poiba oil fbnna a «olid and a liquid comjjound. The oil, 
fihaJce» up with aqutous potash or Ktda^ hecomcM heated, acquires u brown colour, jind 
yiolda to water a small quantity of r<?mn» which does not pre-exist in the oil, but is 
produced ftom it by the uetiou of the alkali (Oerber). Dktilled with 24 pts, water 
nod 8 pta. chloride of lime, it gives off carbonic acid and forms chlomforni. Dis- 
tilled with k^fpobromite of potassium^ it forms bromofonn. (Cbautard, Compt rend. 
xxxiT. 48 j.) 

s. Rydrochloratf of Copahene or Copaivtne, Htfdrockhraie of Copaiba oil, 
Camphn de Copahu, C'*H".2HCb— This la the solid hy<lrochlonitc ; it i« prepared 
by passing dry hydrochloric acid gaa tln^ugb dehydrated oil of copaiba, aepaniting 
the crystalline muss, which ia dejjosif^d therefrom on eooliujf, from the brown oil, 
pre«aitig it between filtering paper» mixing it« aolwtion in ether with alcohol of »[»cvific 
gravity 0*6o, and washing with alcohol the ciyi^lalliue nmoa which fieparutcs. 
(Blanchet.) 

Hydrochlorate of copahene fbrma short, transparent^ right rectangular prisms {re- 
sembling chlorate of potassium, according to Bhmchet), which molt at 77^ C, (Sou bet ■ 
raDaadCapitaine). They are inodorous (Blanch et, Soubei rati and Cupitaine); 
hare a fkiot cam phorous odour, and an aromatic bitter taste. (Gerber.) 

The hydrochlorate, heated to 140°— 160<>C., ^ven off a large quantify of hjdrochlonc 
acid gas (Souheiran and Capitaine). When set on fire, it bums with a bright 
llame (Gerber). NUric aeid, heated with it^ is said to give off nitrogen giut (B lan- 
ehet). Oil of miriol, with aid of heat, dissolves if, and deposits it again in the crys- 
talline fonh on cooling ; at a stronger heat, the solution gives off hydmchJoric acid gas. 
Heateii with suJphidc of kad^ it yields an oil baring an aUiaoeoua wlour. Its alcoholic 
solution is precipitated by nitrate of aiiver or m$rc«r(m» nitratf. (Blanchet.) 

It is iosolublo in water and in cold alixthol, sparingly soluble in hot alcohol, ea&ily 
aolable in other (Blanchet), The alcoholic iolatioa leaves when evaporatcti a thick 
^it «Kt^h «mells like balsam of copaiba, and appears to hold in lolution undccomposcd 
d rate of copaiba oil (Sou b ei ra n and Ca pi tain e,) 

yfate of Copahilc^if.^-^Tlkh is the liquid portion of the product obtained bv 
Itfatiug copaiba oil with hydrochloric acid. It always coutaiiis in solution a jjortion 
of the solid compound^ which cannot be separated from it (SiUibeirrin and Capi- 
taine). It is a black, viscid oil, smelling like castorpum* and without action on 
polansed Hffht (Sonbeiran and Caniiaine), When diBtilknl, it gives off hydro* 
ehloric add gas, and yields a colourless oil, whidi is a mlution of hydrochlorate of 
eapahene (Soubeiran and Gapi taine). It bums with a faint odour of hydr^v 
ehlorie acid. It give* np a portion of its hydrochloric acid when shaken up with water. 
It ia soluble in alcohol and ether. (Gerber.) 

Para-copaiba Oil (Soubeiran and Capitaine [1840]. J.Pharm. xxvi.TO. — 
Post el t, Ann. Pharm, btix, 67,)^Thia oU occurs in a variety of copaiba bolimTO from 
Brazil. It is sepanitetl by distilling with water, aiid the oil is dehydrate with chlorido 
ot calcium (Po§solt). It is a transparent^, colourless, viscid oil, of specific gravity 
O'^l (OB98 according to Soubeimn and Capitaine), boiling at 250^ C. It amells like 
the balsam, sad has a sharp burning taste (Fob sell). Rotatory power 28*553° to 
th^ leit (Sonbeiran and Capitane). It dij^solves in all proportions in fth^r^lemk 
easily in abiolute alcofwi^ still less in eommt^n ofeohd. 

The oil becomes yelloTvish when boiled, afterwards brown, tbickt tenacious, and 
charred (Posse It). Chl&ririe converts it^ with evolution of hydrochloric acid, into a 
^-'low sticky mass. The oil dissf>Ives iodinf without detonation. With/wmrw-gf nitric 

d, it detoaatee even in the cold ; but nitric acid of specific gravity 1-32 resiuiflesa it 
Only wifli aid of heat. Dilute nitric acid, heated with the oil, dissolvea it completely 
after a f*^w duyi, giving off nitroua acid, carl>onic acitl, and other volatile acids. From 
the solution of the oil in nitric acid, water throws down, after evaporatiou. a reddiMh- 
yellow acid resin, sparingly soluble in hot water, eaailT soluble in alcohol and ether, 
vhiltfl a peculiar add remains dissolved, which, when the solution ia coticentrated by 
CfTa|iotation, crystallises in elender, colourless, transparent laminae^, easily soluble in 
fPXttfV alcohol, ether, and rock-oU, inodorous, having a bitter taste, and a slight acid 
reaction (Posselt). The oil absorbs hydrochloric acid tjas with avidity, turning 
bn^wn-red and fuming in the air, but not depositing any crystals on cooling. 



I char 

F*only 




18 



COPAIBA-RESINS. 



rs. (Sohweizor, Po^. Ann. xrn. 784; xxi. 172,— Rose^ 
thid. miiL 83. — Hess, Ann. CL Pharm, xxii. 140 — Fehling, ihid, xl. 110. — 
Posaelt, ilnd, liii. 67.) — Copaiba bakam cooUins B4?Tcral rvaim which remain be- 
hind akiter the distillatioD of the Yoktila ail ; certain samples of thia bakam haTO been 
£>mid to contain pecoiiar resina. 

The reains obtained £rom ordinary copaiba balsam maj be separated into a cmtal- 
lisable resin called copairic acid (the a-fesin of Berzelivui), and aa uncr^fitolliaabk 
fi-remD, The latter, which fonna but a small proportion of iJie whol% remains behind, 
when tho entire mass of resin is treated with cold lock-oil, aa a brown nnctnons maaii, 
aaaOj eoliihle in alcohol or ether. 

CoFaiTiC Acid. Q^hu i*ic add. a-resin of Berreltm. C^H*0*, or C^B** O*, — 
Thia ayatallisable resin exists in copailm balsam to an amount Tmymg from 20 to 66 
pes cent. It is the constituent which determines the himlcning of the balsam 
trjT magnesia, an effect which, howerer, does not take place if the proportion of 
eopaiTic acid ia below 50 per cent (Frocter), According to Schwcizer, the acid maj 
be pr^ared by disBolTiDg the entire mass of resins obtained from copaiba balAam in 
aqoeona ftfwmftiiin^ and leaving the solution to evaporate in u cool plHce. Crystals 
then nepaiate which may be obtained pure by washiikg with ether and recTystaliisation 
fyam alcohol. Or the leainovta man is heated with cold rock-oil, the solution left to 
craporate, the rttidue disBolTcd in alcohol, and the copaivic acid left to dystaUise by 
spootaneoits evaporation* Or the entire mass is diflsolred in alcohol, and the solution 
left to eraponitc. 

Copaivic acid forms colourless rhombic crystals, soluble in strong alcohol ; the solu- 
tion »addens litmus. It dissolves easily in ether, ia oils both fixed and volatile, and in 
SD^hido of carbon. It is decomposed by heating. 

The acid dissolves in aqneons fixed aJkalis and in ammonia* The alcoholic solution 
mixea without decomposition with alcoholic potash or with strong aqtteoos potash ; 
but, on *jit^ir>g a larger quantity of water, a precipitate is formed 

CopaiTic add appears to be monobasic. The caicium*salt, C'*H**CaO', is a white 
precipitate, which separates on mixing an alcoholic solution of the resin containing 
a little ammonia with alcoholic chloride of calcium, and then adding water. Co- 
paivate o/tead^ C"H*PbO', is obtained h^ mlmng the alcoholic solutions of the resin 
and acetate of lead, as a white, fusible, sbghtly crystalliae precipitate. Copaimte of 
«f7ver, CP'H'AgO', separates, on mixing the solution of the resin with an alcoholic 
solution of nitrate of silver mixed with a little ammonia, as a white ciystalline preet- 
eipitate, sparingly soltibte in alcohol, easily soluble m ammonia, easily fumble, and 
taming brown on exposure to light. 

OxTCopAtvic Acid. C»H»0*, or J?O.C»*if"0»,— This acid resin was found by 
FehUng in a sediment deposited frt>m a turbid copaiba balsam from Para. By solu- 
tion in alcohol and slow evaporation, it is obfained in colourless regular crystals, whose 
primary form is a rhombic prism having the acate summits truncated. It becomes 
strongly electric by friction ; dissolves readily in ether, less readily in alcohol ; melts 
at about 120° C. When the solution of the resin in ether and alcohol is quicklTr eva- 
porated in aflat dish, and stirred at the sametime^ a hydra ted resin, U^R^QKHK}, 
or C*//^C*. 2^0, sometimes separates as an amorphous powder; it has the same com- 
position as the oxysilvie add described by Hess, but differs from it in propertii^. 
This hydrat.ed resin softens in boiling water ; it forms with bases the same salts aB the 
anhydrous resin. 

Oxyoopaivic add, heated with nitric amd^ ^^^ off carbonic and nitrous adds, and 
yields two products, a resin and a new add. The resin, said to be C"//*0". is light 
yellow, has a strong and disagreeably bitter taste^ and unites with bases. The acid 
ifl firee fhmi nitrogen, of brownish colour, deliquescent, very soluble in water and- in 
alcohol^ easily decomposes! carbonates, forms soluble salts with the alkalis^ a sparingly 
soluble salt with baryta, insolable salts with lead, mercury, and silver ; the lead-salt 
has the compositiou 2Pb^.C»*H"0^ or AFbO.C^W^O^* (? X 

When oiycopai vie acid is evaporated to dryness with ni^c acid, there remains a 
pitchy mass, part of which dissolves in alcohol, leaving a humoi'dal substance having 
the composition C*H*0". 

Oxycopaivates, -^xy copwvic acid dissolved in alcohol exhibits an acid reaction. 
The oxycopaivates of the hlkali-metals are solnhle in water \ the ammoniacal solution 
gives off all its ammonia by evaporatioD. The ieed-mli, C*H"PbO\ or PbO.C^H^^O^, 
is obtained at a white precipitate on mixing the alcoholic solution of the resin con- 
taining a little ammonia with an alcoholic solution of acetate of lead The ttihtrmtt^ 
C"H^AgO', or AgO.C^B^^O^^ separates as a white amor|*hous precipitate on mixing a 
solution of the acid m aqueous ammonia with excess of nitrafe of silver. 

Acid Cofaiba-besin.— This lesiit was found by Martin and Viguo (J. Pharm. 



COPAIVENE— COPAL. 19 

1842, p. 52X in a oystalline deposit of copaiba balsam, which diasolred in hot alcohol, 
bat separated oat again for the most part as the solution cooled. As it has not been 
further investigated, its identify or non-identity with one of the resins prerioosly de- 
scribed, mast for the present remain undecided. 

From clear copaiba balsam, Martin and Yigne prepared a resin different fiwm the 
crystalline substance. 

Indiffbjbsnt Copaiba-bbsins.— Whether the /S-resin (p. 18) belongs to this 
group is doubtful, inasmuch as it is said to dissolve in alkalis. 

In a veiy fluid copaiba balsam of peculiar constitution, Posselt found, besides para- 
copaiba oil, two indifferent amorphous resins, the first of which (containing 60*3 per cent, 
carbon, 8*3 hydrogen, and 31*4 oxygen) was soluble in weak boiling alcohol; the second 
(conta^iing 82*0 carbon, 10*5 hydrogen, and 7*5 oxygen^ diasolred sparingly in boiling 
absolute akohol, separated out for the most part on cooling, and was insoluble in dilute 
alcohoL Neither of these resins combines with alkalis. (Handw. d. Chem. ii [8] 799.) 

COPAZVXwa. The camphene contained in the crystallised hydrochlorate of 
copaiba oil ; it has not yet been isolated (p. 16). 

COPAXVIO AC9IB. See Copaiba Bbsdts. 

COPAZVZUnra or COV AZVT&i. Syn. with CoPAima. 

COPJk&» A valuable resin of which the best ooach-vamish is made. It exudes 
spontaneously from several trees, namely, the Bhu8 copaUina, a terebinthaceous tree, 
native of North America, the Elaocarpua eopali/er, which grows in the East Indies, 
And the Ifymenaa verrucosOy which grows chiefly in Madagascar. French writers 
likewise give the name copal to the resin of the Hymerufa Courbaril, growing in Brazil 
and the West Indies ; but in England and Q«rmany this resin is called animi (see 
voL i p. 296). There is altogether a considerable amount of discrepancy in the state- 
ments respecting the trees wmch furnish copal. 

Copal generalfy occurs in flat pieces, rough on the outside, and of various shapes and 
sizes. Its physical properties vary to a certain extent according to its origin ; but the 
lumps are, for the most part, opaque on the outside, transparent intemaDy, of yellowish 
to yellowish-brown colour, sometimes nearly colourless ; turbid and translucent lumps 
also occur; insects and parts of plants are not unfrequently enclosed within the resin. 
Copal is hard ; it has a very lustrous couehoidal fracture, is easily pulverised, does 
not cake together even when chewed, but becomes rather soft at 60° C. The specific 
gravity of copal varies from 1*045 to 1*139 according to its origin, and perhaps also 
according to its age. 

The solubility of copal in different liquids varies also with its origin, American 
copal being much less soluble in alcohol^ oil of turpentine, and oil of rosemary, than 
East Indian or African copaL By exposure to the air, especially when pulverised and 
placed in a hot air-chamber, it absorbs oxygen, and then becomes more soluble in 
alcohol and in oil of turpentine. The solubility is also increased by melting the copal 
at the lowest possible temperature ; but Amencan copal is moro difiicult to fuse than 
the other varieties, and sometimes remains so insoluble as to be quite useless for 
making varnishes. Anhydrous copal in the natural state is but very sparingly soluble^ 
but swells up to a tough elastic substance when boiled. In pure ether, copal swells 
up to a transparent jefly, and afterwards changes to a syrupy mass. If this mass be 
heated to commencmg ebullition, and alcohol of specific gravity 0*82 be added in 
Bucoessive small quantities, a clear solution is obtained ; but if the alcohol be added 
cold or all at once, the mass coagulates and docs not dissolve. Copal is but partially 
soluble in aulvkide of carbon, but oil of caoutchouc diBaolTeB it easily, even in the cold. 

Copal dissolves in strong sulphuric and nitric acids, but is decomposed by those adds 
if only slightly heated. 

The statements respecting the solubility of copal in caustic alkalis TKry considerably, 
doubtless because the experiments have been made upon different varieties. Accord- 
ing to Filhol, neither ammonia nor potash dissolves it in the cold ; but if the liquid is 
heated to the boilins point, the resin coagulates and floats on the surface in the form 
of a spongy mass, w!^ch does not dissolve, even after several hours' boiling, — because 
the compound of the resin with the alkali, though soluble in pure water, is quite 
insoluble in water containing e:tcess of alkali 
The following analyses of various kinds of copal have been made by Filhol : 

ri!i5!ll»?*ii!? Copal from CalcutU, In Copal firom Copal from 
Calcutta Td7 white, flat lumpa. Bombay. Madagawsar 

^ * . 

Carbon . . • 80*66 80*34 80*29 79*70 

Hydrogen . . 8*77 10*32 10*52 10*40 

Oxygen . . . 1057 9-14 9*14 9*90 

100-00 10000 100-00 100*00 100*00 

I ' 2 




20 



COPAL VARNISH. 



Filbol ha« obtained from Ea«t Indinn copal, fire distincfc reiiiiiB, same of which 
however pass into others by oxidation, so that thi?y may bo regarded as different 
oxides of the same radicle ; Tiz. : 

a^resin: Soft, fusible at the heat of the water bath; solwbk in alcohol of 72 per 
cent,, aI»o in ether, and in oE of turpentine; forms, with bases, reflinatea aoluble in 
ether, bait (excepting the potass in in -aalt) insoluble in alcohoL 

^re*in: Soil, fiiiible below 100^ C. ; Bolnble in all proportiottfl in alcohol, ether 
and oil of turpentine ; forma reainates solnblo in ether, insoluble in absolute alcoboL 

y'Teain: Whit«, soluble in ab&olute alcohol and in ether; less fusible than the 
preceding ; forms resinates insoluble in aleohol and ether. 

B^esin: White, insoluble in alcohol and ether, soluble in alcoholic potash; very 
difficult to fuse^ 

t-retin: Gelatinous; insoluble in ^ menstruAi 
These resins yielded by analysis : 

Cirbon. 
ii-reflin . . , 77 76 to 76*94 
^resin , . . 7604 — 76-85 
7-r«sia . . . 80*63 — 8070 
f-reuD . . - 81-16 — 8168 
The kad-salta formed feom tbe first two yielded : 



Qaddeoflead 



26-17 to 26*32 



1012 to 10*24 
1008 — 10-86 
10.43 — 10-66 
10 54—10*43 


26 to 28 



Th<«a analyses were perhaps not made with definite substances. The quantities of 
lead'oxide found in the riMJinatea are nearly the same na in the lead-salta obtained ftom 
the turpc'D tine-resins (»ee Titbpkntike) ; hence it is probable that the reainous con* 
atituentfl of copid tire similar in composition to the reaius of turpentine. (Gerh. iii. 
069 ; Hiindw. d. Chem. ii. [3] 202.) 

GOViL^ VAJUnsSp Copal may be dissolTed by digestion in linseed oil, ren> 
deted drying by qtiickiime, with a heat very little leas than suMcient to boil or decom- 
posa the oiL This solution, diluted with oil of turpentine, forms a bt^autiful trans- 
part'nt Farnish, which, when properly applied, and elowly dried, is Tory hard and 
durable. This Tarni«h is appbed to snuff-boxes, tea-Ttoards, and other utensils. It 
preserves and gives lustre to paintiiiga, and greatly re» tores the decayed colours of 
old pietureii, by filling up the cnicks, and rendering the surfacea capabJa of refiecCing 
li^ht more uniformly. 

Mr. Sheldrake has found, that camphor has a powerful action on copal; for if pow' 
dered copal be triturated with a littk? camphor, it softens, and becomes a eoherent 
maiNB ; and camphor, added either to alcohol or oU of turpentine, renders it a solrent 
of copal. Half an ounce of camphor ie stifficient for a quart of oil of turpentine, which 
should be of the best quality ; anil the copal, about the quantity of a large walnut, should 
bo broken into veiy small pieces, but not reduced to a fine powder. The mixture should 
be fiflt on a fire so brisk as to make t he inixturo boil almost immediately : and the Teasel 
should 1h* of tin or other metid, strong, shaped like a wine-bottle with a long neck, 
and eafwiljle of holding two quart*. The mouth is stopped with a cork, in which a 
notch is cut to prevent the vessel from bursting. It is probably owing to the quan- 
tity of camphor it contains, that oil of lavender is a solvent of cojial Camphor and 
alcohol dissolve copal still more readily than camphor and oil of turpentine. 

In the 5l8t volumo of Tilloch** Magazine, Mr. Comclina Varley states, that a good 
varnish may be made by pouring upon tho purest lumps of copal, reduced to a j^ne 
mass in a mortar, colourless spirits of turpentine, to about one-third hiplier than the 
eopal, and trituratinej the mixt ure occasionally in the course of the day. Next morning 
it ximy be poured off into a bottle for use. Suceeaaive portions of oil of turpentine 
may thus be worked with the same copal mass. Camphorated oil of turpentine, and 
oil of spike-hiTendcr, are also recomni*indcd as separate solvent^ without trituration. 
The latter, however, though very good for drtiwirtga or prints, will not do for varnish' 



ing pictures, as it dissolves the paint underneath, and runs down while drving. 
Fat vamuh. — Take copal 16 parts, linseed or poppy oil made drying with Y ' 
oil of turpentine 16. Melt the copal in a matrasJt, by exposing it to a moderate beat; 



pour then upon it the boiling- hot oil ; stir the mixture, and wben the temperature 
has fallen to about 200° F. add the oil of turpentine heated. Strain tho whole 
immt^liately through linen cloth, and keep tho varnish in a wide-moutlied bottl^^. 
It becomes yary clear in a little while, and ia almost colourless when well made. 
This varnish h applied on coaches, also generally on polished iron, broaa, cojiper, and 
wood.— tJ. 




COPALIN - COPPER, 



21 



k 



eOPA&ZV* FogfU comff Highqat^ resin. — A fossil reain found in roundish 
lumps in the blue clay of Highgate Hill» It resembles copal resin in hiuxlneas, colouTp 
lustre, and trauaporency, and is llkowise but sparingly soluble in ak-ohoL Sp. gr. 
1010 (Johnatou)y 1*05 (Bastick), It emit^ a rcsinouja odour when broken, Tolati* 
lis€s in the Air at a gentle beat^ and barns easily nitli yellow flame and much amuke. 
Sulphuric acid diasolwa it with purple-brown colour. Hitrw acid converts it into an 
add resin, which is preeipitatinl by wat<?r aa a yellow powdert fonna soluble salts with 
the iilkali-metaJa, insoluble with all the rest Accorfling ta Johnston's analysis 
(PhiL Mag. [3] jdr. 87), it contains 85*4 per ceut^ ciu-lmn, and 11-8 hydiog^-n, 27 
oxygf»ii, «Dd 0*13 aah, whence may be deduced the formiila C^Il^^O or C^H^^CP. 
(lohuBtOO, from the old atomie weight of carbon, C« 612, calculated the fomiida 

Kenngott obtained from India a resin whi<?h agreed with the Highgate rpsin iu 
properties, and had a specific gravity of 1053 ; it contained fragments of Alpine plants 
and insects. An antdysis by Dufloa showed it to contain 8573 per cent carbon, 11 60 
hydrogen, and 277 oxygen. 

Another renn, reeembling the preceding in external appearance, occurs in tlie form 
of flattened dfooi or ooatings on calcsparp on the walls of a dyke of trap at ilw lAA 
lead mine in iHorthnmberlaDd called aettUng Stonts, It has a pale jetlow to deep 
red colour, with pale gfften opaleseenee. Sp. gr. 116 — ^164 ; hard, but brittle ; does 
not melt at 40(F F., but bums in the flame of a candle with empyrfcumatic odour. It 
is insoluble in wat-er, and nearly insoluble in alcohol It contains 86 13 per cent. 
cfurhoDf 10 85 hydrogen, and 3 26 ash = 99'2ir numbcri agreeing nearly with the 
formula Cm (Dana, ii. 267.) 



Yell&tc Copperag.—A hydratcd basic ferric sulphate, 2Ff'O',550* 

-♦- 3^0, occurring in the district of Copiapo in the province of Cofjuiinl>o, in northern 

OuU, in six*siided tables and grains^ which cleave readily pariillel to the base. Also 

i'Jftkotis and incrwtting. It is translucent, with yellow colour and vitreous lustre* 

> Bef«ral other basic ferric 8ulphat<?s are also found native, vis, St^pticitf and Fihra- 

Jtrriit from Chili, Pitticite from Fahluo in Sweden, and MUy found near Gcaler in 

the Harz ; they are formed by the weathering of iron pyrites^ and are probably not 

definite compounds. (See Sclfhatbs.) 

COFVn- Bynonymes r Kupfer^ Cuivrf^ Ct^rumy VenuB, Symbols and At4>niic 
weights: Cu = 316 {cupncum); Ccu — 73-2 {cup'^atum,) 

Copper has been known from the earliest times, and appears to have been used for 

weapons, tools, and agricultural implements much earlier than iron. It was indeed 

mtich more likdy to attract the att^ntiott of primitive nations than iron, as it is found 

liatnrally in the metallic state, is malleablo and ductilu immediately sift-er fusion, ami 

acquires considerable hardnfiss when mired with other metals, Isidoms, who wroto 

at the beginning of the seventh century, says : " Apud antiquos priore aris quam ferri 

[ ^O^nitm iwns, mn qnip^ pdmi proscindebant terram^ sere certamina belli gercbant.** 

I The Bomansi who oVtained it from the island of Cjrprus, called it iBs cyprium^ a term 

afterwards shortened into cyprium, which ultimately became cuprum. Tlio Gr&eka 

called it x^*^^% ^^Tii Chdcis in Eubcsa, another locality whence it was obt^tined. 

Both tho Greek x*^*^^^ '^^^ ^^^ Koman «j appear, however, to have been used indif- 

; ferently for copper, bronze, and brass. Pliny uses the word as in both senses, as 

appears from the following passages: *^ Mb fit a lapide feroso quem vooant cadmiam," 

wliich probably refers to brass ; and again, *' Fit et ex alio lapide quera cbalcitem vocant 

in Cypro, nbi prima fnit ajris inventio," where a6 appears to Biyuiiy copper. 

Ooeurrtnee. — Copper occurs very abundantly and in a great Tariety of forms. It is 
^mnd in the metallic state ; also as oxide, cbJoride, carbonate, phosphate, sulphate, 
silicate arsenate^ and vanadate; as sulphide, sometimes alone, hut more frequently in 
combination with the snlphides of other metals, as in copper-pyrites, purple copper, 
\ ftnd tlis several varieties of fahl-ore. It is found to the amount of 0*1 to 0*2 per cent. 
iln aui^ ipectmens of meteoric iron. According to Walchner (Compt rend, xxiii, 
1 12), coppor is as widely distributed in nature as imn, though lees abundantly, small 
qnaotlQei of it being invariably found in iron-ores, in soils, and in femiginous mineral 
watem It has also been found in sea-weed (Malagnti, Durocher and 8arzean, 
Ann Ch. Phys^ [3] xxriii 129), a fact which proves its existence in sea-water, — in Oie 
Vlood of various Ascidia and Cepkaltypoda (Harless, Chem. Oaa. 1848, p. 214), in the 
Iblos Uood t!>t lAmndm Cyd&pi (Genth, Pogg. Ann. xcr* 60>| and in very minute 
I qnantttj iu th© bodies of animals of higher orf^anisation (Jahresb, d. Cbt-m. 1847-8, 
i pp. 871, 874 : 184D, p. 630). According to Od ling and iJupre (Guy's Hospital Re- 
ports, Oct, 1868), small quantities of eoTOer are constantly found in floor, straw, haj*, 
Bleat, egg;^ i^^^t-'^t^f ^«i other articles of food ;' in the animal organism, it exists in 



pro|H)rtioQ&Ily large qtiflntitj in khe Hver itnd the Iddnrpit whilt> the blood oontainf 
only tTii(Jc« of it. 

Of %h^ Tariotis copper mtnerak above cnnroerated, a few onljT can be rega^led aa 
ores of copper, tUftt is to say, m minomb from which the metal can bo profitably 
extracted. 

1. Native copper.— Metalb*<s coppe? in not nnfrequently found in copper ores^oe- 
during in isokt«d particlee, thin laminip, dendritic pieoea, and Bometim w in Bolid blocbi. 
Pieces of ore are sometimes found consisting of a nuclcos of met^dlio copper oo&t4Ml 
HncccasiTely with rod oxide and with carbonate of copper. Large mMoefi of natire 
copper have been found on the coast of Lake Superior near Kewenaw Point, in veins 
that inteTBect the trap &nd sandstone. Dr. Fwej states, on the attthoritj of Professor 
Brosti of Yiilo College (U.S.), that in ISflft, 6000 tons of copp<?r were proenred froni 
these deposit^}; one mass found at Minnesota, weighed SOU tons. Another mass 
thrown down in 1853 at the North American mine^ was 40 fi^^t long, and wuighed 200 
tons. Native copper is found also in Siberia ; in the island of Naboe, one of the Faroe 
groun ; in many of the Cornish mines; near Harlech, North Wales ; and in Brazil, Chili, 
and Fern, The North American native eopper contains about ^ per cent, of ailver, for 
the most part intimately mixed with it, but sometimes in Tiiible gnuuft, Inmpe, or 
threads. The ChiE copper alao contains silrer, sometimea to the amount of 7 or 8 per 
cent 

2. Osidea. — The r^d oxide, Cu*0, or Ca«0, is found in Comiph, South American, 
and especially in Australian ores, A lai^ vein of it was worked at Chesey in France^ 
but it Uf now nearly exhaiusted. When pure it contains 88'78 per cent of copper. 

The htack oxide, Cu'O, or CuO, occurs at Kewenaw Point, lAko Superior, forming a 
vein in conglomeratCt fipom which about 40,000 lbs* of ore have been extructed ; but it 
is now exhausted. The pure oxide contains 79*82 per cent copper. 

3. Cardan a l«**-*-The ^rten carbonate or Tmthchite, Cu'CO* + H*0, or CuO.CO' 
+ CuOMO, occurs abundantly in many localities, especially in Siberia and in Sonth 
Australia: the pure mineral contains 07 33 per cent, of copper. The blm caHtonaU or 
dMfmUt CxL^RCQ*, ^T 2{€uO.Cif^) + CuO.HO.in found in considemble quantity afc 
Chessy, near Lyons, and has been imported from South AuBtralia in admixture with 
the groen carbonate. When pure it contains dd'16 per cent, of copper. 

4. Sulphide*, — Vitreom or ^rey SuJpkidc of Oopp^r^ Cu*S, or {7m*5, occut« frf?- 
quently in ComwalL It contains 79'79 per cent* copper, but is generally aasociated 
with iron to the amount of '5 to 3*33 por cent. 

Purple capper, — This term is applied to several minerals consisting of cnpnms and 
ferric sulphides, combined or mixed in various proportions* Eammebberg divides 
them into three classes, the first comprising ores containing S6 to Sfl per cent, of cop- 
per, the second 60 to 64 per cent., and the third 70 per cent. They form valuable 
ores, and are abundant in Cornwall, Sweden, and many parts of North America. The 
mineral 3Cu*S.Fe^S\ or 3Cu*S.Ft^^^ occurs disseminated in the cupriferons shale of 
the Mansfeld district of Pnissian Saxony, and in Pennsylvania. 

Copper pyriUs or YeU<^ capper ore, CuFeS, or Cu' 5. i^'f'S*.— Copper 34'S per cenK 
This is the most abundant ore of copper, and is found in large quantities in Cornwall 
and Devonshire, at Tallinn and Atvidaberg in Swrcden, in fiiba. South America, and 
many parts of the United States. The Coraish mines yield annually from 150,000 to 
160,000 tons of tbia ore, fiwa which 10,000 to 12,000 tons of pure copper are smelted: 
the Cornish ore is imbedded in quarti ; that of Sweden in gneiss. 

FaM-ore, or True Grtp copper art. — ^This terra includes a considerable number of 
minerals consisting of pmtofiufphtde of copper combined with the sulphides of anti- 
mony and arsenic, tlio Clipper be ing more or less replaced by iron, rinc, sdver, and mer- 
cury. The copper varies from 30 to 48 per cent, according to the foreign metals 
present ; the mercury varies from 2 to 16 per cent Fahl-ores not containmg silver 
are the richest in copper, containing 48 per cent ; in the most highly argentifeioaa 
ores, on the other luud, some of which contain 31 per cent sibreE, the proportion of 
copper may l>e as low as 16 per cent — Bournonite is a sulphantimoDite of copper and 
lead, containm^ 417 peroeat Pb, and 12'7 per cent. Cu, sometimes with a smafi quan- 
tity of iron. These ores occur in nnmcron*) localities, and often very abundantly. 

Alaeamte, the natire oxy chloride of <ropper irom Pern and Chili, and ckryaocolUit 
the nativo silicate found associated with other copp^ ores in various localitica, bn 
likewise n»ed for the extractkin of the metal. 

The sulphuretted ores of copper are found in veins traversing the ancient roeka. 
Near these primitive veins are often found beds of copper ores^ evidently arising from 
decomposition of the mineral in the vein by the action of water. The first change 
consists in the conversion of the sulphide of copper into sulphate by the oxickting action 
of the air contained in the water ; the sulphut^* then diiwlves, and is carried away by 




COPPER. 



2a 



the water; and when tbia cnpreoiis BolutioQ filters tkrotieh beds of caxbonato of ealcium, 
or remainB in the cavities of suck caicareouB bedE^^ double docompofiition takes place, 
resoltiiig in Ibe formation of Eulplmte of calcium, which is carried away by tlm? 
water» and earbonate of copper^ which is deposited. If thia reaction tiikea place at 
a high temperature, oxide of copper is deposited, instead of carbonate ; and, if or- 
ganic KubstanceB are present, the copper majr be reduced to milphide or red oxide, or 
ereii to the metallic stat«. Thia reaction mar e!jtpjain the occurrence of beds of ear* 
bonate aikd oodde of copper bo frequentlj found in the neighbourhood of reina of 
(N>ppc!r pjntea, and of the anmll cxyBtala of sulphide of copper, which are found dia* 
seminated through certain bitmmnouB schista^ aa in the Hanefeld district of Prussian 
SaxoDj* 

Preparation of Metatlie Copper, 

The processea of copper-smelting Tory greatly according to the nature of the ore^ 
The treatment of the oxidfs and carbonates of copper m comparativelj simple, the 
reduction being effected by meltinp the ore in contact with cnarcoal, or other car- 
rbonaoeooB matter, and a siiccoua flux. The oxide of copper haa, howcTer, a strong 
itendeiicj to unite with the silica, forming a highly cupiiferoua elag. To prcTcnt the 
Umb ih^oe ariaing, it ia necessary either to add a strong base, with which the silica 
i]BiBj unite in preference to the oxide of copper, or else a quantity of copper pyritea, 
I Iron pyrites, or other milphuretbed ore, the sulphur in which may combine with the 
I <^76^ •'i^i reduce the copper to the metallic state, thereby preTcnting it from form- 
I ing a silicate. The first method is adopted at €hee^, where copper ores, consisting 
cf malachite, aznrite, and red oxide, mixed with daVr hydrated oxiae of iron, and cala- 
mine, lu-e smelted with coke and lime. The second method ia practised at the copper 
works in the Ural, where a mixture of copper ores, consisting of natiTe copper im- 
bedded in quartz and magnetic iron ore, malachite, red and black oxide of copper, &&, 
L and copper pyrites, is smelted in blast fumacea fed with wood. The metal obtained 
[ hf these operations ia an impure copper, called bluek copper {8ckfttarekt^/er, mdvrs 
Imoir), whicn is purified or refined by processes to be hereafter described. 
I S^iipk^tiretUd copper ores require a much mors complicated treatment^ depeuding 
[ mainly on the fact that copper has a greater affinity for sulphur, and a less affinity for 
[ oxygen, than iron and the other ractaJa with which it is associated. They are first 
[roasted, to conrert a considerable portion of the sulphides into oxides ; then the 
lOftst^ ore ia melted, either in rererbcratoiT or in blast furnaces, with addition of 
[ alag and other fluxes, if the ore doea not already contain a sufficient proportion of 
I flOicatca. During thia o^>eration, the oxide of copper formed in the roasting is rccon- 
Ivated Into enlphidei while the iron which remained in the rooated ore as sulphide, 
taeee to the state epoxide. A slag is then formed, containing the greater part of the 
on in the ore, and a sulphide of iron and copjp^r (coarse mttal^ Eokstein, matte 
I cmvrrueey, containing the greater part of the sulphide of copper in the ore, and a much 
■nudler proportion of sulphide of iron. The coarse metal, which may be deacribed as 
ft concentrated copper ore, is now again roasted or calcined, and the roasted pro- 
diict ia Igain fuaed with the slags of other operationa, frequently also with addition of 
oiidiaed copper ores, when such are available. This operation yields a second slug, 
containing a laigar proportion of iron, and a Be<x)ijd regnlus containing a still krger 
proportion of smplude of copper than the flrst : and by repeating these calciuiiig and 
melting operations, a certain number of timeSf Tarying according to the nature of the 
ore ana the construction of the furnacea, a regnlus ia at lengtli obtained, consisting 
ftlmost whoUy of sulphide of copper. Now wncn this compound is roasted, with free 
aoeeas of air, the first result is to oxidise both the sulphur and the copper, the eulphur 
mainly going off as sulphurous acid, so that alter a while there remains a mixture of 
sulphide and osdde of copper, which compounds, at a certain temperature, decompose 
^aai other in such a manner as to yield sulphurous acid and metallic eopp^ {^'j?* 
2Cn^ + Cn'O = SO* 4- Cu»). The product of the operation is a regnlus of metallic 
copper, Tanring considerably in purity according to the particular series of operations to 
vnich it has been subjected, and known as coarse topper^ blister copper, Schwarikupfer, 
cmvre noiTf &c This impure metal is lastly suljeeted to the rtjinmg process, which 
ia more or less complicati^, according to the de^eo of purity of the coarse copper. 

The HTeral operations of caleiniiig and melting are perfonned either in reTerbem- 

tory ftimaoeei or in blast fiiniaoea similar to those u«ed in the smelting of iron, only 

' sot ao huge. The choice of one or the other form of luraace, is deteimined by the 

» ctrcnmstanees of the locality. Where there ia abundance of coal, and of good fire-clay 

[ far the construction of the furnace, m in the neighbourhood of Swansea in South 

Wales, r«T*Tbcratory furnacea are used ; hut where these conditiona are not fulfilled, 

as in most of the continental localities where copper is smelted, the preference is given 

to Uast furnaces, partly bccaose they are lefis quickly corroded by the action of the 



24 



COPPER. 



melted elag, |iartlj becaoso thoy ensure a more economical consumption of tbe fupl, 
and'lctti loBS of copper m the elugs. 

CappeT'SmdHn^ in Eewrhtratory Furnaces .* Welsh Process, 
O op p cg-BDadting has been carried on in the British Isles from reiy c^arlj times. Thero 



of eoppar-worki in Northumberlautl, Cumberland, and Yorktfbire in the 
zeign of Edward III, ; and smelting works were subseqiifntly estjiblbhed in Lnncajihlre, 
Blaffbrdshirft, Gloucestcrsliirc, Cornwall, and the neighbourhood of Brifitol, in most 
I in the neighbourhood of copper mines. At all these old works, blai^t-fumacea 



appear to haye been u^ed^ In the *ievent«>nth centnrj', copper^smelting was ejct^n- 
mvdy carried on at Neath in South Wales ; but at present the lai^ei^t c«pper-worka in 
Great Britain are at Swansea, a locality eminently adapted for the purpo«e, not onjy 
by the preat abundance of coal in its ncinity, but also by its poyition on the coaet^ at 
a short distance trom Cornwall and Devonshire, the counties ^m whitrh the largvvt 
quantities of copper ore are obtained, and easily accessible to venselfl conveying ore 
from Spain, South America, Aastralia, and other i>arts of the world* 
The ores smelted at Swmiuea may be divided into lave classed! : 
L Sulphides of copper, mixed with a large proportion of sulphide of iron, and only 
a Tery small quantity of oxidised eopper-compounds. The gangne is formed of quartz 
and earthy matters. Proportion of copper from 3 to 16 per cent. 

2. Cupriferoiis pyrites, similar in composition to tho preceding, but containing a 
lar^ger proportion of copper, viz. 16 to 25 per cent, 

3. Cupriferous pyrites containing very little iron pyrites, or any other subst^ince 
hurtful to tlie qm^ty of tha copper, but a laiger proportion of oxidised oopper^om- 
pounds. 

4» Open consisting chiefly of oxidis<?d coppcr-compoTind^t, mixed with copper pyrite« 
and purple copper. &angue quartzose. Proportion of copper 25 to 45 per cent. 

6. Very rich oxidised copper ores, free from sulphides and injurious substances ; they 
contain frL>m 60 to 80 per cent, of copper, in the metallic state, and as oxide and car* 
bonate. These choice ores como principally from Chili. 

The facility with which the reduction is effected, as well aa the qutility of the metal 
produced, depends in great measure on the iiidicioufi admixture of these several varie* 
tie* of ore. When a plentiful supply <jf oiidee or carbonates can be obtained to mix 
with the sulphides at a certain fetage, the number of operations from the first calcina- 
tion to the refining muy he rednced to six; hut when only snlphurons ores are at hand, 
eight, or even ton or twelve opemtionB may be rt^quired. The following is an outline 
of tlie process, as carried on under the mo#t farounible circumstancea. 

I. Ctilmiatian, — The process is commenced with ores of the first-clasa, consisting es- 
sentially of the sulphidei of copper and iron. They are calcined in a largo reverbcratory 
furnace^ called the calciner, of which j^. 132 represents a horizontal section, and 
^. 131a Tertiral section through the line X Y of the plan. The hearth of the fiirniiee 
is formed of fire-brick, and i« either sqnnre, as represented in the fipure, or more fre- 
quently oblong, about 20 feet by 12 feet beiug usual dimensions. The vault desci>nds 
ropitlly from the end above the flro-placo IV to the opposite end R, where the goaes 
enter the tall chimney. The furnace is charged with firom 3 to 3^ tons of ore, by the 
cast-iron hoppers T, the charge being nnifomtlv spread over the hearth bv means of 
long iron tools called stirrinff rafMrg, introduced by the side doors />, which are four 
or ftix in number, according to the length of the furnace The projections between 
these doors serve to prevent the chnrge fnjm getting heaped np in the intervening 
space, a position from which it coul J only lio removed by stirring from the opposite 
side. The fuel used is anthracite mixed with J of its weight of bituminous coal, to 
make it cake together and form a moss of a due degree of porosity. The air passing 
upwards through this heatcHl mass of carbon, its oxygen is completely conTerted into 
car Iconic oxide, which, together with the nitrogen, passes on through the body of the 
furnace, and burns at the expense of the air, which enteifl by the aperture a {fiff, 132), 
situated near the fire-bridge, and by smallor ai>erturca in the side doors ; the vault of 
the ftumioe thus becomes Med with a long flame of carbonic oxide, burning in contact 
with the stratum of air containing excess of oxygen, which enters by the apertures 
above-mentioned, and spreads itself over the hearth. The ore on the hearth is thias 
constantly immersed in a stratum of oxidising gas, kept at a high temj^varature by the 
combustion of the carbonic oxide just above it. A considerable portion of the sul- 
phur in the ore is thus converted into anlpharous acid, which escapes by the chimney, 
the copper and the iron being at the aarae time partially convert45d into oxides. The 
calcination Lists from 12 t<» 24 hours, the charge being stiireil from time to time to 
expose a fresh surface to the oxidising atmosphere, and the heat regulated so as not to 
permit the particles to clot or sinter together, the tendency to which diminishes, how- 



* 




COPPER. 



S8 



«Ter» as tho calcioatioji procredfi. Wfai*ri the calcination is completed, the ore ih rak^ 
ioto the holes, r r, on the sides of the hQurth, tLrongh which it falls mto the vault U 
bdoWf where wat^er is thrown upon it. 

Fiff. 131, 




Fiq. 132, 




An idea of the cliAaffe which t-tikos j I 



inlng proicpi*f(, may he gatheretl 



from the foUowing anilvaes of sampler ft r.nv anl 'uli med on\ hy Le Play. {Descrip- 
i turn deaprocidis mikdlurpque$ emjdoyis dans leFays de GailcsjMur kt fabrication du 
\ Cmvrt, Paris, 1848.) 



Bate ore* 

Ouproiw oxide, Ca*0 


0-4 


Copper pyrites 


. 227 


Iron pyrites, FeS . 


22*4 


Various BidphidcB . 


10 


Sesqaioxidti of iron . 


0'6 


Varioas oxidi» 


0-3 


Silica , . . . 


3f3 


E;irthy ashes - 


20 


Water and carbonic acid ii 


I 


oombinatioD 


05 



Calcined ore. 



Scsqnisulphide of iron (Fe*S") 



Sulphuric acid combined 



6-4 
11*2 
11-2 

0-6 
IM 

0*6 
34*3 

2-0 



filtaiaipliene oxygen eon^imod hy) ,^.q 
tlui mtKnint of ore in the ctdcinatioD \ 



&42 78'1 

j ETolTcd J Water and earbouie add 0*6 
I as gas. (Sulphurous acid. . 21*4 
100^ lOUO 



The loss of weight which ownured during ealciDatioD, was found to be 7 '2 per cent 
ftlid tlic loss of smphur ol & per cent, of the total in the ore. 

2. Mdtinq of thit calcined orf. — This process is performed in a reYcrheratory 
, fbrnaoe, called tho ore-furnace, represented in figures 133, 134. 

I H»\ is a mixture of 2 pts. iinthmcite and 1 pt, bituminoua coaL The teuipcratunj 



26 



COPPER, 



it xaiMd higlier th&n in the calcining furnace, by increasing the draught The 
tieartli is fbrnied of slag, and ha» a. doprvasod basin at B, into whick the melted metal 
sinks. The charge consists of the c-aiciucd product of the preceding opemtion mixed 
with meial alag^ a produet obtjiined in opcnition No. 4^ and sotnetiniea with uuroa^ted 
ore of the thira class (p. 24), and u ce^rtidn qnaiititj of fluor spar to render the slag 
more fluid. The oxidea and Bulpbidea decompose one another,the products being 
diieflj fiilpbide of copper, oxide of iron, which passes into the ^lag oa ailicati^ and 
BalpJiimnig add, which escapes^ the oxidation of the eulphnr b&ing alao jpartljr dne, aa 
ill the pireoeding oporAtion, to the action of the air in the furnace. The proceaa ii 
eomplc^ in ftrar or five hours. Tho products consist of a regulus, called amrBe metal, 
eootdnin^ the greater part of the copper as adphide and a certain quantity of sul- 
phide of iron, and a slag neh in iron and containing numerous siliceous fragments 
diMeminated thioogh it^ which girc it ii muddy consistence. Thia slag is raked out 
of the furnace by a rabble introduced through the doorp, and fails into a seriea of 



Fiff. 133, 




134. 




rectangular caTities U, formed in a bed of siind. At the same time, the melted i 
met4il collected in tho baain B, is nm out by a tap-hole at the bottom into a 3 
Toir R, containinff watw, whereby it is gmnukted. 

The coarsr m^ 6r; containa about 33 per cent of copper. It is brittle, and easily 
pttlvensed: its fntcturcd amfeice is non-crj-atalline, uneven, more or less gninuJjir, 
generally vcHicubr, and of a bromo colour. The following analyaea have been made 
of it by Leplay and by Napier. 



COPPER. 



27 



Comfoiiiim of Coarse MeUtL 



(mean). 

33-7 

33-6 

10 

07 
03 



Copper 
Iron 



Kipter. 

211— 39-5 
33-2— 36-4 



' Klekel, cobalt, mangiineiid 

Tin 

I Anomc . « * . 

I Bolphttr . . - . .29-2 Sulphiif . . , , 45*fi — ^25*0 

Slag medittQically mixed . . 1*1 

The ftkgf called ore-furnace slttg, gonorallj consists of a Tiard, brittle, black mfttrix, 
in which are imbedded ghaqj angular piec^e* of white quartz. It frequcxitly con- 
tttini Bmjdl shots of coarse mettd. If tbe«e are numtfmns, the &lag must bo n>melted 
is mibaequeiit opemtions. Its avenige oompoaition, m detenuini^ bj Loplaj, is qjs 
follows: — 

CompoaiUon of Ore-fumaet Sl^. 

Qunrtz in admixture 30*5 

Silica in combiDatioa .300 



Alumina 

Pixjloxide of iroo 

Lime . . , 

Magnesia 

Various oxides (of tin, mangauese, nickel, and cobalt) . 

Flnorine I'O 

Calcium 
Copper 
Iron . 
Sulphur 



1"0] 
0"6) 

0-c) 



2*9 
285 
20 
06 
I'i 

21 



2-0 



lOO'O 



I This elag has nearlf tlie comnomtion of a forrous mctasiHcate, Fe'SiO* or IFeO.^iO', 
It appears, then, that in tne melting process in thi^ ore-fumace, a counidemble 
rtioD of the iron of the calcined ore is^ removed in the elag, and the whole of the 
Sfsopper^ excepting the aouill portion which pasaefl into the akg, ia coooentrated in a re- 
alm oantaining, on the aTera^e, as mnch copper as pure copper pfrites (p. 22). The re- 
QctioD of the aeeonioxide of iron in the ciilcined ore to protoxide is due to the action 
of the solphur, which is oxidised to sulphurous acid at the expense of the ferric oxide. 
Any copper that may exist tn the state of silicate in the mrtai jslfiff, forming part of the 
chiu^ of the ore-furnace^ is converted into cuprous sulphide by mutaitl decomposition 
with the sulphide of iron, which is alwaja present in this furnace, and passen into the 
cowemetaL 

&. Calcination of the granidaied coarn meUd^ — This operation is performed in a 
ealeiiuxr, with &ee access of air, the charge bein|^ f^qentlj stirred and turned orer. 
The calcination ia complete in about 24 hours, the heat being gmdually ruined 
towaids the end of the process. No eatisfact/ory analysis of the calcined product has 
jet been made. Leplny, howcTcr, found that, in a sample of coarse metal coutainitig 
33*7 per cent, copper, 34*2 iron, V5 of Tarious other metala, 29 6 sulphur, and M »lttg» 
the p r op ort i on of sulphur was reduced by calcination to 16*4 per cent The sulphur is 
erolfea aa anlphurous and sulphuric acids, 
' 4. MiUimi^ of the cafdrnd coarsr inttu!, — ^The calcined product. No. 3 is melted with 

addttioil of matters rich in oxide of copper, namely, roaster and rejinery slags, and a 
qautity of ores of the fourth class (p. 24), consisting of oxides and carbonatee of 
eoppcr. The furnace is similar to the ore-furnace {Ji^. 133), excepting that the hearth 
luui BO baain. The process is conducted in a «imilaj manner, excepting that it ie con- 
tinued two houn lon^, and the heat is nuaed higher. The reaction consists mainly 
in a double decomposition between the sulphide of iron and oxide of copper, whereby 
oxide of iron is formed, which paasea into the sla^ as silicate^ Aud sulphide of copper, 
which forms the regulue ; Tery little milphnrons acid ia eTolTcd. The slag is 
skimmed off, and drawn omt of the fiirnace through the end opening below, where 
sand-bMs are placed to receivp it The regnlus is tapped off into sand-moidds imme- 
diately in front of and below the tap-hole of, the furnace. 
The oompoflition of the regulus produced in thiti operaJtion, Tanee with the proportion 




COPPER. 



of oside of copper mixed with the calcined coarse metoL When a Bufilcient quantity 
erf oxide and carbonate can be added to decompose the whole of the sulphide of iron 
present tlie regidos haa Tery nearly the compoeition of cuproua enlphide, Cu^S, the d»* 
compoaitioa taMng place aa represented by the equation — 

Ca'O 4- Fe^ + ^SiO« = Cu*S + Fe*0.*SLO*. 

The regnliti ftxnned under these circnmstancea ia called white mrial. It has a dark 
bluish grey coIouFi Mid faint metallic lustre, ia compact and bnttlo, with iineTren, gra- 
nular, and mope or leca crystaUino fractnrc. It contains on the aTcrage 73*2 per cent 
copper. A sample analyaed by Leplay, of specific graTity 6-70, contained 77 4 per cent 
copper, 0'7 iron, with traces of nickel and cobalt 01 tin and arseuic, 21-0 Bulphur, and 
0*3 alag and aand. Pure cuprous sulphide contains 80 per cent copper, (See SiiLPHroKS 

OF CoPFBtt AXD 1bO», 11. 77). 

The alag» called fneia^-alag, is brittle^ compact, and occasionally Teiy crystalline, of 
blufr-grey to bronze yellow colour, and in dining ti metallic lustre. An analysis by 
Leplay gaTo : 



Silica »3*8 

Alumina * - • • • ^'^ 
Prt>toJcide of iron . . . 6fi*0 
Cuprous oxide , * ,0-9 

Yarioua oxidca * . ,21 
TJm a • . • « • 1'4 



Magnesia » * . . . 0-3 



1000 



If the proportion of oxidised copper-compounds in the chaigie ia less than what is 
requtrrd for producing white-metal of the composition abore giTen, the rwgulus will 
contain a considerable quantity of iron, constituting, &om its colour, what is called 
hlu£ mttat; white-metal indeed passes insensibly into blue metal as the proportion of 
iron increuet. 

Mine metal always contains metallic copper diffused through it in very minute 
particles, and protruding into the int-erior of cavities in the mass, in delicate bair-like 
maments. The manner in which this metallic copper is formed is not very clearly 
underetood ; but the reduction appears to take place during cooling, and to depend 
upon a reaction between the sulphide of copper m the regmus and the oxides in the 
ilag. When the oxidised copper-compountk in the charge arc in excess, some of the 
copper is likewise reduced, and a reg^ulus is formed similar for tht* most part., in cora- 
poBitiOQ, colour, and properties, to whito metal, but exhibiting on its upper atirface 
namGfous pirn pie -like excreaceRcea^ whence it is called pimnk^mtial. 

5. Roajttntg of the White or Sim metal. — In this operation, the sulphur, which hod 
hitherto been retained in union with the copper as an age at of concentration, is 
finally expelled in the form of sulphnioua acid, and at the same time certain foreign 
metais, namely, arsenic, antimony, iron, cobalt nickel, tin, &c., are removed, by con- 
version either into volatile oxides, or into silicates, which pass into the slag. The 
proiH^s consists of two successive reactions, which take place in the same fiimace : 
1. The direct action of the air on the metal kept at a tempemture near its melting 
point ; 2. The reaction of the oxide of copper thus formed on tho sulphides not de- 
compoaed hy the roasting, whereby sulphurous acid is evolved, and copper reduced to 
tlio metallic state. The metidlic copper thus obtained ia called biiattr ctyppv, from the 
appdirance of its surface. There is also formed a slag very rich in copper, called 
roasitr-^g^ which is added to the fumace-chax^ in the smelting of the odeined 
grantiiiied coarae metal (No. 4). 

The operation is performed in a reverberatory furnace simile to the melting 
furnace ( J%f. 133), hut having a side door by which the pigs of regulus are introduced : 
and lateral openings near the fire-bridge for the admisaion of air. The rich oxidised 
ores of cla8S 6 (ii- 24) arc added to the chai^. In half an hour, the pigs begin to 
melt ^^^ the temperature is eo regulated that the fusion may be complete in six or 
eight hours. The surface of the melted mass appears to hoil, owing to the escape of 
eulphuroiii* acid, produced by th© mutual decomposition of the oxides jind tiulphides. 
The ahig which forms on the snx&oe of the melted regulna, is skimmed off twice during 
the operation, once immediately alter ftiffion, and a second time just before tapping. 
After a while, the temperature of the furnace is lowered sufficiently to allow the 
Mgulufl to solidify. When it has become pasty, its surf see ia thrown up into 
crfttars^ in consequence of the continued erolutiou of gsa, whereby the extent of 
surface exposed to the air is greatly increased and the oxidation assisted. Finally, 
the rogulus is again melted into sand-moulds, where it solidifies in the form of biUtlr 
copper. 

The following are analyses of blister copper and vonster alag» 



COPPER, 



29 



Sliaer copper, L*pl»jr. 

Cespper 98*4 

Iron , • , . , 07 
Niekel^ colialt^ maiigaiieso * 0-2 
Tin ttiid un«iLie . ♦ .0*4 
Sulpbur 2 

lUU'O 



Xirpler. 



97-5 
07 
It) 
0-2 

100*0 



98-0 
0*5 
0*7 
0"3 

oa 

lOO'O 



98a 
0-8 
00 
0-1 

^0 
lOO'O' 



Hoattfrtlag. L«plAf. 

Silica . 47'6 

Atrnninn 3'0 

GnpKNia cmde . . • 16-9 

Perronii oztde 280 

Oxidea of nickel^ cobalt, nmnganeao . , . .09 

Stannoiis oxido 0*3 

Lune and magnesia ....... traces 

Metallic copper .,....•, 2*0 

986 

Aceotding to Xepky, roaster-itlag coat&iiifl on an average 20 per i^eut. of copper, 
indiudTe of that present in the metallic state. It is TedmLir, more or less scoriaeeous, 
of daxk reddiah-bpown colour, vimed hew and them with greyish hJack, and without 
metallic lustre. 

fi. Billing. — This \a the last operation, and Ha object ij to remove the foreign 
naetala and tho remainder of the Bnlphiir. The rcagenta bj which tlmi change is 
efiectod are, the oxygen of tho air, and the siliceous matters of the hearth and walla 
of tho fonuu^e, together with those which are ftirniahed by the sand adhering to tho 
pigB of blistered copper. The refinery furnace is simihir in **on»tructiuii to a melting 
fanaoe, excepting th tit the bottom inclines gnidnally from all sides towariJs the dcepwit 
part, which is near the end door* and there i« u large door on one sidcp but neither a 
tkolis in tho loof nor a side tap-hole. Tho furnace m ehai^d with & or S ton^ of 
pigs of bliBt«red copper, which are melted and exposed for about 15 hours, to the 
oxidising action of the air which enters the furoace. The oxide of copper formed, 
acts either immediately, or after combining with aitica, on the sulphur and metab mere 
oxidable than the copper^ thereby oxidi^iing and cansing them to pass into the alag, 
together with the excels of oxide of copper. The slag m skimmed off through the end 
opening. 

The copper, tbm freed from foreign metals and Bulphur, is, howercr, in a peculiar 
state, being intimately mixed with a conidderable quantity of red oxide, which destroys 
it0 inaUeability ; in thi£» state it is called dr^ copper. To deoxidise and t&mhen it^ a 
quantity of anthracite, or free-burning coal — charcoal was formerly used — is thrown on 
the BuHaoe, and after a short time, a large pole of oak or birch, the greener the better, 
i« thrust into it, and kept down by fixing a prop under the end which pro trades from 
the fomaoe. Under tho influence of the high temperature, tho wood gires off a large 
quantity of rednciDg gases, which cause the metal Co boil yiolrntly, carrying the 
particles of carbon below its sm^aoo, and greatly accelerating the reducing action. 
After twenty minutes of this treatment^ which is callod polinff, the refiner takes out a 
sample of the melted metal in a small ingot -mould, and when the ingot is cold, places 
it on an anril, and tests its quality by hammering. As soon as it is found to posseaa 
ibm characters of good metal {toti^h pitch), the surface is again skimmed as &st as 
possibls, and tho metal ladled out into moulds. Should the metal, daring the process 
of iMillwig, become more or less dr^ by oxidation, it is again poled for a short time, 
Ji; on tlie eontrarf, the poling has been continued too bng; the copper again becomes 
brittli^jprobably because the oxides of certain other metals, lead, antmiony, &c. present 
in smul quantity, are reduced by the poling, and the copper consequently becomes 
aUogred with these metals ; in this state it is said to be otrrpoled. To remedy this 
defoefet the surface is uncovered, and exposed for a short time to oxidstion. When 
tbs oopper is intended for roUing, a certain quantity of lead may be advantageously 
added to it just be&re ladling. Tho proportloD used is rery variahle, sometimes as 
mnch as 80 Ibai of load to 6 tons of copper, sometimes not more than from 14 to 30 IIm. 

The rtfimry'da^ is Yvrj rich in copper, A specimen analysed by Leplay contained : 



Bilica 47-4 

Alumina ..... 2'0 

CTv^irons oxide .... 36'2 

Faiooi oxide .... 3*1 

Oiidfla of nickel, miinganefle,&c. 0*4 




Stannous oxide 

Lime . 

Magnesia 

Shots of metallic copper 



0-2 
10 

0*2 
9-0 

00-6 



30 



COPPER. 



A specimen examined by Dr* Percy contained 579 per cent, copper existing as 
cuproaa oxide, and 2'05 met-alHc copper ; mukmg a total of 00*65 per e«iit* ooppen 

It htm already befn obsfrred, that when a plentiful supply of rich oxidiaed ores 
cannot be obtained, the calcinationB and fusions hava to be repe^ited a greater Dumber 
of times: thus^ instead af Jtt once subjecting th© white or blue metal resulting from 
the melting of tho calciiHKl coarse metal to the process of rtfOsthifflBa aboTe described), 
it IB ueoeefiiLiy, under such circumstances, to calcine it again, and subject the calcined 
product to an additional melting before commencing the roasting. 

The meitd-'skig (No. 4), and likewise the ore'/umace slag when it contains namerons 
shots of regulufl, are some times remelted in order to concentrate the regulus which 
they contain. 

Lastly^ we must notice the process of making what is called ** best selected copper/' 
which is merely a Tcry pure metal used for tine purposes^ especialty far making the 
beet brass. The process consists in melting one of the numerous yaneties of blue mftal, 
and lapping it into a series of moulds or sand-beds. The pigs nesxest to the furnace 
then contain the greater portion of the metallic impurities, while those more remote 
contain a pM^r regulus, which is then roasted and refined. Another method is to 
ro&at the blue metal, or pimpk metxti^ till about half the copper is n-dooed. Th« 
residual metal, called rrguiCt ie*^ result ^ or s^ngt/ rcguk^ 10 Efterworda roiibted mxA 
refined by itself. 

Copper Sfneiting in Blast Furnaces, 

This is the method chieiy adopted on the continent of Europe, as in Sweden and 
in Germany. 

Swfdish process, — Tb<^ Swedish copper ores^ the principal mines of which are at 
Fahlun, in Dalecarlia, and Atvidaberg^ in Obtrogothiaj^ consist of copper pyrites mixed 
with A lajge amount of iron pyrites and siliceous minerals. 

L Roasting or C'o/^rinfl/ibfi.^The ore is iirst rmuted either in kilns formed by walls 

built in the manner shown in fy. 135, 
Ftg. 136. ^j, in ^^^^ m'niimdal heaps, most fre» 

quently the fatten In either ease, a bed 
of wood about 12 inelioa high is formtni 
on the ground, and on this the oro 
\s piled in alternate layers with small 
charcoal, to the height of 2 or 3 feet in 
the kibs^ and 10 or 12 feet in the heaps. 
By this means, a large portion of tho 
salplmr is burnt away, while the iron 
is chiefly oxidised, as in the Wi4sh 
process of calciuaUoii. The roasted ore should retain sufficif^nt sulphur to fumisli, 
when smelted^ a regulus yielding fk^m 20 t^o 30 per rent, of copper. 

2. Fugitm of the rouMtd orc^Tbe roasted ore is next mixed with Uack copper sJag 
li product obtained in the fourth operation, and containing a laige amount of irc»D. 
The ^portions should be so adjusted as to vieid, when smelted, a wpruliis containing 
from 2 (J to 30 per cent, of copper, and a slag naving nearly the composition Fe*8iO'. or 
3FeO»2@tO', which is found to possess the proper degree of liquitlity. The mixfiire 
of ore and black copper slag is smelted with coke, or a mixture of coke and charroal 
in a eafjola {S(^hachtoftn\ called the ore-funiace, ahont 18 feet high^ the fire being 
urged by a blast. The regulus obtained is a mixture or compound of the subsulphidest 
of copper and iron. 

3. RoaMing of the regvlits^—The regulus is next roasted in a range of kilns con- 
structed on each side of a medium wall in the manner r©pi«»ented in Jig. IZ5. The 
roasting is repe4ited four, five, or even six times. When the first firing is finished, the 
rcguln» is transferred to the next kiln, then to the next, and so on till it is roasted 
*' dead " or *' sweeL'* No charcoid is addod in the first firing, but in the second 1^ 
measure of charcoal is spread upon the wood, and the quantity is incresiaed in each 
successive firing, till, in the sixth, 12 meJL-^urea of charcoal are- added, forming thre« 
layers, indnding that on the wood. The entire roasting generally last'^ from seven to 
eight weeks. Daring the roasting, oxide of zinc is formed from sulphido contained in 
the regulus. 

Fusion ffvr Mack oopper.— -The roasted regulus from the last opcmtion is next 
Bmclted in the Uack capptr fimiace, which is ^\m a cupola, but of smaller dimensions 
than the ore-funmce, iu admixture with a roasted regulus {thin n^gidns) obtained in 
preeetling operations, also with f^iwry *?<^*, fomace-residues contJiining copper, and 
ort'furmtct shga, sometimes also with addition of quarta. The products are thu^k 
e<fpper {SchwarUkup/cr\ an impure metallic copper^ 80-ffl*lled from ita superfickl crust 




COPPER. 



SI 



of black oxide; thin rtguJm, containing from 65 to 72 per cent, of copper j and hlnck 
\ topper slag^ chiollj consisting of silicate of iroD, but contstinlng about 1 per cent of 
I copper. This elag is added to the charge of tho ore-furnace in a 8uba«quent operation, 
and the thin regulna ia remelted in a sabseqiaent fusion for black copper. 

The bUck copper haa lastly to be refiwdt to free it from sulphur and foreign, metala. 
This ia effected, aa in the Welsh proceBS^ by melting it under a layer of charcoal, and 
\ pubjeetiiig it at the same time to the action of a current of air. The arrangements are 
I similar to those oaed in Qermany, which will be present! j deaciibed. 

Th* following are analyeea of the bl{u:k and refined copptr of Atridaberg, made at 
the atnitig school of Fabian : — ' 

Bltck eopp«r* Refined copper. 

Copper . . 94*39 99-460 

Iron 204 0111 

Zinc 1-65 — 

Cobalt and nickel 0-63 0-110 

Tin , , 0*07 scarcely a trace 

Lead O'lB ditto. 

Silver Oil 0^065 

Gold ....... not looked for 0-00] 5 

Sulphur 0-80 0*017 

AzBoaio traco 



09-78 



99*7645 



] The greater part of the oobdt ia separated in the refining and becomes concentrated 
fin the ala^L, 

Mansftld proeesM, — The copper ore of the Manafeld district in Prussian Saxony 
' I of aigillaceons schista {Kupfrr-schiefer), largely impregnated with bitumen, and 
I copper pyrites diaseminated in small crystals. The schist is first roaeted in 



%, 136. 




^. 1*7. 

mmn hi.h ii.i,,ii».iiii.i|[iii,nif|t) ^^ 




IfyTunidat heaps on bo^ls of wood. Yery 

rSttZe fiid is required, the fire being kept up 

r^ the combustion of the bitumen contained 

lia the 9chijit« The roasted ore ia then 

I mixed with from 6 to 8 per cent, of fluor 

I ipar, eopriferoiis alagfhjin mibsoquent stages 

Icn preceding operatioua, and often with small 

Vqnantitiee of cupriferous schists containing 

f carixmate of lime. This mixture is smel ted 

: in enpolaa firom 15 to 20 feet high, heated 

I witfi coke. Fig. 136 is a vertical section 
of the furnace, passing through one of the biyrrrn. Fig. 137 is a frtmt new, with » 
iectiou of the Iowct part of the shaft This lower part of thi- crucible is formed of sdi- 
«eo« grit, the npper part of brick. The fUmiice (tho orc-furuuce) has two tuiftrt* 1 1, 



32 



COPPER, 



ploeed «itlu»r on the eamo side of the sbftft (as in the figure), or on op^»ostte sides. At 
the bottom ot the crucible Am two apertun-s, oo\ which upo opened alternately to allow 
the Ibsed products to ruo into the baHi'iia C C. The funuice is filled with ore tmd fiutt 
ID altenukte la^yen. The regulus and slag ore constantly numin^ from the furnace into 
one or other of the basins C C. The slag is moulded into krge bridts, which B«rve 
for baHding. The regolos (Eohsl^in)^ v^hich doefl not amount to more than 3^ ot 
the weight of the roiiited ore, i^ composed of cuprous sulphide, Cu*S, and ferrous 
sulphide, F^S, and eontains from 20 to 60 per cent, of copper, aceerding to the niituiv 
of the ore. The poorer kinds of regains contaiuiiig from 20 to 30 per cent, of copper 
are roasted three times on beds of wood^ and again smelted with ala^ from preceding 
operationA, thoao being selected which lay immediately above the regains in the 
basins Q &. A new regnlus (Spur»iein)Aa tbua obtained, containing as largo m propor^ 
tion of copper as tbo first regidtia of the richer ores. 

The richer reguli (Spuratein and Biinrntdn) ore roasted six times in succession ou 
beds of wood in kilns, — brick-walled kilnn like those represented in %. 136 (p. 3l>]. 
Dtiring the roaating a oonaiderable quantity of sulphate of copper is formed, which is 
removed by liriviation and crystallised. 

The roasted and lixiviated re^na ( Gaarrott) is now smelted with a due proportion 
of sUg in a blast furnace, similar to that represented in Ji^, 1 36, but smaller. The pro- 
ducts are Uack (dipper, a rich regulus {Dunnstein), which is added to the second Tegulns 
obtained in the preceding operation, and slag. The black copper is removed in the 
form of discs, by throwing water on the surface so as to form a solid crust. It eontalDS 
about ^6 percent, of copper, 3 or 4 per cent of iron, and small quantities of silver and 
antimony. 

The quantity of silver in the block copper is generally si^cient to render its extrac- 
tion ppofitahla This is effected by a prtwcss cxilk^ eii^taiion^ depending on the fact 
that load forms with silver a more fusiblo allny than witb copper. The urgent if eroua 
cop|>?r is melted with h iid (argentiferous lead, if it can bo had), and the mt^ted alloy 
is either suffered to eot>I very wbwly, in which c^ise the copper soiidifiea first in com- 
bination with a portion of the lea^l, while ilw reatof tholead» in combination ^nth nearly 
the whole of the silver, remains liquid, or the whole of the fmfed mass is c-ast into discs', 
which are then ■nbji'cted to a gradually increasing beat, the effect of which is to melt 
out the silTer in combination with part of tbo lead* while an aUoy of lead and cop[>er 
remaitui in tbesol id state. The argentiferous le-ad is then cupelled to separate the 
BtlTflr. (See SavBu,) 

The alloy of lead and copper thus obtained* still, however, retains a small portion 
of silver, which is sometimes separated from it by subjecting it to a higher tempesrature 

in contact with acunvnt 



Fig. 138» 



of air, whereby a fresh 
portion of lead contain- 
ing silver is separated, 
not, however, in the me- 
t^illic state, but in the 
form of Htharge, 

Et^nivg, — The black 
copper thus de^ilverised 
is reflnod in a reverhera- 
tory fbrnace constructed 
like a cupelling furnace* 
The metal is fused on 
the hearth a. Jig. 138, and 
fiubjeeted to the oxidising 
action of a blast of air 
fn:»m the tuyeres n, juj. 
139. A red slag is then 
formed containing the 
foreign metals, iron, lead, 
^c, and a considerable 
quantity of cuprous o%- 
ide ; it is removed from 
hrne to time by the door 
p. The refiner juflgcs 
of the progress of the 
operation b^y taking out from time to time, a anioH quantity of tho> melted metal, 
and examining it in the manner to bo presently descriheil. Wlien fho proc<?«s is 
flniiihed, the melted copper is mn off into the bitsins h h, nnd a little water is poured 




COPPER. 



88 



upon h to fbnn a mat on the rarfiioe, which is then lAken off in the form of a dise 
called a rosette. 
When the black copper does not contain silver, it is not sabjeeted to the eliquation pzo- 

Fiff, 139. 




cess, bnt is inunediatelj refined, in a small ftimace, called a r^ning hearth, of which 
fig, 140 is a yertical section and>^. 141 is a perspective view. 

It consists of a hemispherical crucible C, about 2 or 2J feet in diameter,and 15 to 18 
inches deep, and made of English fire-clay mixed with sand, and well beaten down. It is 
soironnded bja raised platform, having an opening A, which can be dosed by a door. 



Fig.UO. 



FigAAl. 




The cmcible having been dried by filling it with lighted charcoal, fresh charcoal is 
added, the pigs or discs of blade copper are pUiced on the charcoal opposite to the 
tuyere T, and the blast is turned on. As soon as this portion of copper is melted, 
more is added, care being also taken to keep the crucible full of charcoal A channel 
t f, allows the slag produced during the refining process to run off. As the oxidation 
proceeds, sulphurous acid is given o£^ sometimes accompanied by white vapours of 
oxide of antimony. The first portions of slag which run off are of a greenish colour, 
and contain much oxide of iron ; the subsequent portions are of a dark red colour, and 
are rich in copper. To judge of the progress of ttie operation, the refiner from time to 
time dips a cylindrical iron rod into the melted copper, then quickly withdraws it, 
cools it by immersion in cold water, knocks off the hollow cylinder of copper adhering to 
the end, and examines it If it is thick, smooth on the.outer surface, and yellowish-red 
inside, the copper is ** too ^oung," and must be further exposed to the action of the 
blast. When it becomes thin, brownish-red, and crinkled on the outer suiface, of a pnro 
copper-red in the interior, with metallic lustre, and may bo bent several times without 
bi^aking, the copper may be regarded as refined, or nearly so. When it becomes so 
thin as no longer to form a continuous coating, but merely to surround the iron in 
) places like network, and in others to present the appearance of small pointed or 
Vou XL D 



84 



COPPEIL 



Vearded ezensceneefl, the blast should be immediatelj ttopped, as the copper is orer- 
refioed or *' ubergaar." 

When the refining is judged to be complete, the cof^Mr is taken out in rosettes in 
the manner above descnbea 

Toughenina {Hammer^aarmachcn), — Rosette copper, though tolerably pure, is not 
▼erj malleable, because it contains a considerable quantity of red oxide ; in fact, it is 
in the state called " dry " by English smelters. It is sold for the manufacture of 
brass, and other purposes in which it requires to be melted up again. To convert it 
into malleable copper, it is again melted on a refining hearth, under charcoal, but with 
the tuyere less inclined then in the preceding process, so that the oxidising action of 
the blast may not be so strong. There is nottung peculiar in the process, excepting 
that it must be done with great care, so as just to reduce the oxide by the action 
of the red-hot charcoal, without bringing it into the over'tefintd state, lixe the over- 
pol<Kl copper of the English works (p. 29). The refiner takes out a sample now and 
then, ana tests its (]^ualities by hammering. Altogether the refining and toughening 
of the black copper is a more tedious process than that of the English blister copper 
(p. 29.) because the black copper is less pure than the latter. 

The following analytical data in elucidation of the Mansfeld process are taken from 
Perfi^s Metallurgy : — 



Analyses of the Manrfcld Schist 6yBerthier, 
Unbumt. 



RoMtcd. 



Silica 


, , 




400 


SiHca . 


. • 


. 60-6 ' 43-8 


Alumina . 




. 10-7 


Alumina > 
Magnesia 




. 23-4 17-2 


Ferric oxide 




60 


• • 


Carbonate of lime 




19-5 


Lime 


• • 


. 7-8 180 


Carbonate of magnesia 




6-6 


Oxides, copper (CuK)) 


. 2-8 2-6 


Copper pyrites . 




6-0 


Oxides, iron 


(Fe*0«) 


. 9-0 7-2 


PotoHh 




. 2-0 


Sulphur . 


, 


. 4-0 2-4 


Water and bitumen . 




, 10-3 


Loss by calcination . 


. 0-8 60 




1000 






98-4 971 




Analyses of Ore-furnace Slags, 






Helae. 


B«rthier. 
49-8 


Hofltaunn. Rbbinghaaa. 


Silica .... 


67-43 63-83 


48-22 


6000 64-13 


Alumina . , 




7-83 4-43 


12-2 


16-36 


16-67 10-63 


Lime . 




23-40 33-10 


19-2 


19-29 


20-29 19-41 


Magnesia . 




0-87 1-67 


2-4 


3-23 


4-37 1-79 


Ferrous oxide 




7-47 4-37 


13-2 


10-76 


8-73 10-83 


Oxide of zinc , 




• • • . 


, , 


1-26 


1-11 


Cuprous oxide , 




0-30 0-24 


, , 


0-76 


0-67 2-03 


Fluorine 




1-97 2-09 


1-1 






AlkaU (KK)), and 


losa^ 


. . 


. . 


2-1 







99-27 99-73 1000 9986 10084 9872 



Analyses of Ore Furnace Segulus (Rohstein). 



Hotne. 





a. 


6. 


c. 


d. 


Copper 

Iron 

Sulphur 

Zinc 

Nickel) 

Cobalt 


. 62-44 
. 20-49 
. 26-44 


48-26 

17-36 

24*68 

2-90 

0-80 


42-10 

19-26 

26-60 

6-20 

1-06 


31-70 

28-76 

27 80 

4-35 

1-26 


Lead . 
Silver . 


0-41 
0-13 


106 
0-30 


1-60 
0-27 


0-66 
0.16 


Silica , 


. 


1-66 


1-16 


1-66 




99-91 


96-78 


96-02 


96-31 



Ranunelsberg. 



e, 

47-27 
19-69 
26-76 



-!&£! 



/ 

43-62 
23-36 
28-70 

3-46 



4-09 

9m 



Carbon, 

earthy 

matter, 

and 

loss. 



.0-88 



lOOHH) 



COPPER 



36 



Analyses of Concentrated Regulus {8pur8tein\ and Thin Begtdus (Dunnstein) from 
the Black-copper Furnace. 



Oopper • 
Iron . 
Sulphur 
Zinc^ nickel, Sec 




100*80 



Supposed Rational Constitution of the above (BammelBberg). 

Caprons sulphide. . 67*47 . . 46*66 67*69 77*96 

Ferrous sulphide . . 24*75 . . 2611 26*56 23*80 

Sulphides of Zn and Ni . . . . 4*44 3*81 

Metallic copper . . 6*98 . . 21*96 10*08 traces 



Analyses of Slags accompanying Concentrated Regulus (Spurschlacke) and Black 

Copper, 





^ornum. Hoffknann. ^rtbler. Ludi. ( 


;«hrenbeci 


SiUca .... 33*18 34*11 33.6 88*16 


37-90 


Alumina . . . 11*22 8*46 6-6 




Ferrous oxide . . 3203 37*68 61*6 47*22 


49-23 


Lime .... 1714 13*38 5*0 11*66 


9*07 


Magnesia . . . 2*96 4*57 . . 003 


1*47 


Copper existing partially 




as cuprous sulphide . 1*90 0*68 Cu*0 3*0 2*86 


1*59 


Sulphur • . . notdet. 0*46 




98*43 99*34 98*7 99*82 


99*26 


Analyses of the Completdy Boasted Begulus (Gaar-rosi), 






Copper 51*97 


67*69 


Iron 20*39 


10-56 


Zinc and nickel — 


0-67 


Oxygon 13*61 


8*67 


Sulphur. ... .... 2*11 


1*64 


Matter insoluble- in acids 11-92 


9*49 


100*00 


98*62 


Analyses of Black Copper. 





Bertbter. 

Copper • . 95*45 

Iron 8*50 

Lead 

SilTer 0*49 

Zinc, nickel, and cobalt 

Sulphur 0*56 

iWoo 



Hofltaumn. Ebblnghant. 



89*13 
4*23 
0*97 
not determined 
8*98 
1*07 
99*38 



92*83 
1*38 
2*79 
0*26 
1*05 
107 

99*38 



Bivot and PkUUpt^s Method of Copper Smelting, 

This method consists in completing the extraction of the copper by means of me- 
tallic iron, after the greater part has been separated by the ordinary process of reduc- 
tion with coal or charcoal. Napier (Dingl. pol. J. xxviL 293) had shown that copper 
may be precipitated from fbsed silicates containing it, by the action of the electric 
current, the mineral being fused in a bUck-lead crucible connected with the positive 
pole of the battery, and uie negatiye pole being formed of an iron plate dipping into 
the fused mass. It was afterwards found, by numerous experiments made at the 
EooU des Mines in Paris, that metallic iron alone, without the aid^ of the batteiy, is 
capable of precipitating copper from silicates in a state of fusion, just as it does from 

• With other metals. 
d2 



B6 



COPPER. 



saliiie aolaiioni st ordioaty temperatttres. In App] jing thia method to pmctioe, bow* 
erer, it whs finmd tbat the ccxpenditare of iron would he too hc^rj ; henee the tuodifi* 
eattOD abore noticed wa« adopted, of oolj u^ing the iron to complete the rednetioa. 
The proccfli is as foUowa : The ore ia pounded, roasted in the falnning fiunacfl^ and 
then heated till all the sulphates are datxnDposed; by this mnuna na^^ aU the anl- 
phnr if expelled. Th« routed ot« ia then ftiaed with lime and noo-bitaminofia eoaL 
The fusion, which mnat be qniddj oomducted^ vields two prodneta, vis;, reduced cop* 
per at the bottom, and a foa^ mam ot alag or nlimte (ealld the hiUk) floating on the 
top ; this coDtftins the remainder of the copper, mniallj from 2 to 2| pta. in a thoaaand 
(7 in a hnndrfd). Thia residual portion of copper i« precipitot4Hi by the immemon of 
iron bars into the melted alag : the rednetioii occupies ftom three to four honia for a 
ehai^ of $ ctr. The aU& alter thia ti««tment» still retains from 000^ to OOoeS 
t; the copper yield^ by it ia also eontaminated with 0'(KH iron and sulphur, 



latill requires refining. The estimated sariQe by this proceaa, as compared with 
the (urdinaiy method nn&r giren ctreimistanofia, is about 17 per cent; (Jahreab. d. 



Chem. i. 1021.) 

Exiracti&n of Copper in the Wet Way : CEMSNTATlOJf CoFPKa, 
This method consists in predpitating copper from solution bj metalh'c iron. 



It is 



not mu'^h practised, being eoonomical ontj under peculiar drcumatanoea. Tbe drainage- 
water of mines in which the copper ezisis as snlpnidiv often contains solphate of copper 
formed hy oxidation of the pyntea. Solutione of copper are also preptfed arttf&ciallj 
bj treating the poorer oxidised ores with salpburic or hydrochloric add^or bv roaat* 
ing pjrittfcfous ores, and extracting the sulplmte hy lixiriation (p. 32). Dr. Bichard- 
son, of Newcastle, exposes a nuxtnra of pulTensed copper pjrites and chloride of 
aodinm or potassium, occaaionaUj moistenea with water (or lalt-water may be directly 
used) to a temperature not lower than 80^ F. ; the copper is thereby oonTerted into 
chloride^ whidi is lixiTiated with water. Ammonia haa imso been proposed as n solTent 
for extracting oxide of copper from the ores. 

The precipitation is liftfit effected by wrought iron ; cast iron acts more slowly. 
The precipitation is accelerated by agitation, which has the tfSSsct of loosening a basic 
iron-salt which adheres to the snr&ce of the metal, thereby exposing a f^h sor&oe. 
The precipitated ooiiper (cewunta^on copper) is then melted 'and refin^ This method 
is well adkpted to toe treatment of the poorer oxidised ores, like those of Twiata in the 
Waldeck, especially where fuel is scarce. 

According to Ganlthier de Clsjibry and Dechaud, the proeeas may be accelerated and 
the consomptian of iron diminished [? at the expense of xinc] by uie use of a voltaic 
battery, the copper bein^ Idiewise obtained in mora cohenmt form. Copper is some- 
times precipitated from its solutions in the metallic sttite without the use of iron, pro- 
bably Mcanse the solution contains a cuprooa salt, which splits up into a cupric salt 
and metallic copper. 

The precipitatian of copper from the solutions of its pure salts by electrolysis, as 
in the electrotype process, yields the metal in its state of greatest purity. 

For farther details on the metalhugy of copper^ see Percrft MrtaJlur^t/, L 289 ; 
Ur^s Dictionary of Arts, Manufadurtty and Mines, i BIS; Kerrt Huttenhtnde^ 
ii 158 ; Beffnaulfs Court de Chimie^ iii J81. 

Impurities in Commercial Copper, 

A careful inrestigatioii of the nature and amount of the metallic impurilies ia 
numerous Torieties of commercial copper, from THrious sources^ has lately oeen made 
by Messrs, Abel and Field (Chem. 8oc J. xiv. 280)^ the g^eral results of which are 
aa followB : — 

1. Arsmic and gilter are almost inrariable impurities in copper. 

a. The occurrence of bismuth in copper is very general; this metal appears, indeed, 
to be always preaejit, excepting when carbonates of copper hare been used in the pro- 
duction of the metul, as in the Aus^nlian and Bussian coppers. Field lias ahown 
{ihid. p. 2(H) that bismuth ia of Tcry common occurrence in copper minetals. 

3. Anttfnmty is not of so freonent occurpenc© in copper as is generally supposed ; 
the bismuth existing in copper nas doubtless often been mistaken for antimony, both 
these metals being precipitated by water from their acid solutions. 

4. Lead is of Tery rare occurrence in cake-oopper, but appears to be an almost in- 
variable con§tituent of copper which has been manufactured mto she^t or rod. 

5. /«>«, which, like sulphur, exists in conaiderable proportions in mirefincd copper, is 
almost complet4!ly remoT«si by the refining process. 

The special results of the inrestigation are giyen in the following table : -^ 




COPPER. 



37 



Metallic impurities in dijfercnt varieties of Copper, 



Detcriptioa of Copper. 


SlUer. 


Arsenic 


Antl- 
n:ony. 


Bis- 
muth. 


Lead. 


Tin. 


Iron. 


Bawl akd Blistu Coppbb. 
















Chile. No. 1 Bar . . . . 




traces 


, 


traces 






0-68 


1 » . 






i, 


traces 


• 


. 








071 


s .. . 






traces 




traces 








O'M 


4 H . 






. 


O-IO 




traci's 








0-91 


* ., . 






' 


trares 


traces 


traces 








0-fi2 


6 „ . 






traces 


. 


traces 








0-46 


7 ^ . 






i\ 


traces 


. 


traces 








0-.S2 


« n . 






traces 


. 


traces 








0-67 


9 » . 






1 


traces 




traces 








9-64 


z 10 n . 






c 


traces 


traced 


traces 








52 


11 „ . 






1 


traces 


. 










0-62 


u .. . 






i3 


008 


traces 


. 








050 


13 „ . 








OO* 


traces 


. 








0-43 


u „ . 






007 


0-50 


traces 








0-51 


IS .. . 






. 


. 


• 










084 


16 M . 








0-40 


tr«»s 


traces 








1*(>4 


17 ., . 






*• 


0-45 


• 


. 








|•.^2 


18 » . 








traces 




, . 








0-70 


19 .. . 






0-60 


*0-90" 


, 








0-80 


» .. . 






£ 


. 




. 








1-20 


11 » . 






? 

c 


, 


traces 


traces 








0-»l 


» .. . 






• 


traces 


traces 








iro 


n n . 






traces 


. . 


tracffs 








1-90 


M « . 






•a 


traces 


. . 


traces 








104 


» M . 






o 


traces 


. 


traces 








112 


H 96 ., • 






® 


trares 


, 


trares 








1118 


M S7 M . 






■S 


traces 




traces 








0-H4 


« .. . 






i 


0<» 


traces 


traces 








110 


» .. . 






, , 




• 








0-75 


^ Blister Copper , 






1 


o-io 


traces 


traces 








0*32 


Mauaelan Copper . 






traces 


« 


traces 








l-3i 


New Mexican . . 








, , 


, . 


, , 








0-42 


SpanUb, No. 1 . . 






« 


3>31 


070 












^r 1 . . 








2*49 


, , 


trace 








^ ^ 


n s 






, , 


2-15 


. 


0-04 


trace 




, 


Z * . , 






, 


IMS 


, 




trace 




, , 


Z 5 . . 








1*90 


, , 


trsce 


, , 




, 


Z 6 . , 








0-90 


. 


. 








, 


II 7 . . 








0>S0 


, , 










0-21 


z « . 






« 


0-85 


, 


traces 








036 


Swedish, No. 1 . , 






C3 


0^25 


0-90 


, 








031 


„ 1 . . 
ManilUaab . . 






|i 


*I-84* 


traces 
0-65 


Vos* 








0-20 








0-31 


0-17 


0*10 








, , 


Australian (Sydnej) 






^1 




. 


• 








l-Ol 


« (Sydner) , 






. 


. 


• 








0-76 


RinNBD COPPIBB. 
















Chile. (Soci«c6 Itallenne) . . 


. 


. 


. 


. 




0*01 


Chile. No. 1 . . 

S . . . 






|l| 


0-04 
0^03 


• 


• 








0-03 


Spi^h .... 






?r 


traces 


. 


. 








V06* 


„ NO.S, . . 






Qia 


. 










, 


Italian. No. 1 . . . 






6 - 


• . 


. 


trace 










«... 






S 


. . 


. 


. 








trace* 


Tuscan Rosette 






^ 


. . 


. 


trace 








trace 


Russian (CCND.) . . 








Oil 


: '^ 


minute 
traces 


1 • 




. 


No. S 






, , 




, 






0«) 


Hmifarlan . . 








0-36 


'0-99' 


traces 








trace 










006 


0-12 










trace 


Anstrallui (Burn Bum 


1) i 




. 


0-09 


• 










trace 


t^-s.^-^' . 






'(W' 


0-01 
0-01 


, 










trace 
tr4,e 


Norwegian (Altcn) 






trsce 


• • 


. • 










trace 


North American . . 






0-M 


. • 


. 










trace 


No. 8 






0-06 


. 


. 










trace 


Z » 






trace 


, 


. 










trace 


English Tile . 






traces 


0-07 


traces 


*0-08* 








trace 


English Best Select. No 


9 . 




0-03 

0-oa 


0"03 
OKH 


• 


005 
0-04 








trace 
trace 


f» It - 




0*03 


0-01 


, , 


0K>5 








trace 


•• »• 




0*03 


004 


, 


004 








trace 


I* »» J 




0-M 


019 


0H» 


0-06 








trace 


***** 




0*04 


Ol.'S 


a05 


0t)5 








trace 


" ** i? 




0-03 


0-14 


0-02 


0*04 








trace 


'* ** i 




trace 


013 


0-07 


trace 








trace 


** ** 9 




trace 


trace 


trace 


trace 








trace 


•• 10 




003 


0*14 


0-06 


0-06 








ir.«ce 


: : 11 




OiJJ 


0-31 


trace 


0-17 


• 


: : , .r«. 1 



» 



COPPER. 



3iiiJiie iwtpmritU* in different varietieM of d>pp0r— oontuiiied. 



DcKripdMef Copper. 


SUtct. 


Arsealc 


Antt- 
nooy. 


Bis. 
moth. 


LcmL 


TIa. 


Iroa. 


i ; ; 

1 

; 

Ssfsr avdBm. 

SkMC. %V 1 . . 


Ho. 19 . 
U . 
U . 

14 . . 
I» . . 
I«. . 

T Coma. 


0^ 
0H» 
0^0* 
0-06 
(HJt 

OOi 

007 
0^ 
007 
0-OJ 
0^06 
0^ 
009 
0-06 

o<a 

trace 
trace 

a* 

fili 

iif 


0-15 

o-n 

0-14 
0-10 
0-04 
Ot» 

trace 
0^ 
0-19 
0-14 
0^ 
0-10 
0-10 
0^ 
0-19 
0-07 
0i)l 

0-12 
0^ 
0^ 

trace 

0-ao 

trace 
trace 
trace 
trace 


trace 
trare 
trace 

*0-09 

trace 
0-09 
trace 

'o-oi' 

trace 
trace 
trace 

trace 
trace 


0-19 
0-lS 
0-19 
0-19 
trace 
0-04 

0-IS 
0-09 
0-06 
0-04 
0-13 
0-18 
0-10 
trace 
0K>5 
0-OJ 
0D9 

trace 
trace 
trace 

trace 

'trace 
trace 
trace 
004 

trace' 
trace 
0-OS 


007 
0-15 
0t» 
0-06 
0-tf 
0-18 
0-40 
O-lft 
0-38 
0-13 
0-99 


trace* 
trace 

trace' 
trace 
Dotecti- 
mated 
trace 
trace 
trace 
trace 
Uace 

'o-17* 


trace 
trace 
trace 
trace 
trace 
trace 

trace 
trace 
trace 
trace 
trace 
trace 
trace 
trace 

trace 
trace 

trace 
trace 
trace 

|trace 

OOi 

0-04 
trare 
0-19 
0-91 
trace 


" . 




" « 




•• jr ' 




•• . 








•» ' • 

Conii 
Oipper cohi, Gcorg 

: : '^ 

Vev brooM cola 
SoMUb rota. ISM 

Uoiurf htat«;« coin. 


e III. . . 
te IV. . . 

WO I ! 


Old lullan coin 
Bactrtancota(l«l 
I>utcb ecdri . 
Copper rolled lato 


i. c.) 

ihia rlMxm '. 



Phyiical Properties of Metallic Copper, 

Natire copper forms ciystalB belonging to the regular system, viz. cubes, octahedrons, 
rhombic do(le<^edrons, and intermediate forms. Similar forms are exhibited by 
copper crystallised from fusion. When a dilute solution of copper is left for some time 
in contact with wood, the copper is sometimes deposited nom the liquid in cubes, 
octahedrons, and long four-sidea prisms (elongated cubes), acuminated with four octa- 
hedral faces resting on the edges (Wagner, Schw. J. xlvii. 325). In other cases, 
wood precipitates copper in thin ductile plates, with warty surfaces. 

Copper in the massive state is very hard and elastic, and strongly sonorous. It 
has considerable toughness, and may be Waten out into very thin leaves, and drawn 
out into very fine wire. It is hardened by hammering or wire-drawing, but may be 
softened or annealed by heating it to redness, and either leaving it to cool slowly, or 
plunging it into cold water. Its fracture is red, shining, indented, and slightly gra- 
nular ; after hammering, it exhibits a fibrous fracture, with a light-red, silkv radiance. 
The greater the purity of the copper, the greater is its malleability, and generally 
speaking its softness, and the less heat is required to deprive it of the brittleness 
produced by heating. Copper contaminated with other metals exhibits, not an in- 
dented, but a scaly, granuLur firacture, with but little lustre, and after hammering, a 
scaly, dingy red fracture, also with feeble lustre. (For the Tmaeity ot copper, see 
CoHBSXOif, i. 1076.) 

The specific gravity of copper free from internal cavities varies from about 8*91 to S'Qfi. 
According to Marchand and Scheerer (J. pr. Chem.xxviL 193), thatof crvstallised 
native copper is 8*94 ; of electrotype copper, 8*914 ; of pure copper after fusion under 
a layer of common salt, 8-921 ; of unignited copper wire, from 8*939 to 8949 ; of ignited 
wire, 8'930 ; of flattened wire, 8-961 ; of copper plate formed by rolling and aftenrarda 
hammered, 8-962. Copper when cooled from fusion in contact with the air is very apt to 
assume a vesicular structure, by which its density is greatly diminished. This vesictUar 
structure was formerly attributed to a cause similar to that of the " spitting " of silver, 
the copper being supposed to absorb oxygen while in the melted state, and to give it op 
again in cooling ; but it has been shown by Dick (Phil. Mag. [4] xl 409), and recently 
more completely demonstrated byMatthiessen and Russell (ifnd, Feb. 1862), 
that the vesicular structure is produced only when the copper is melted under char- 
coal, and air or oxygen gas likewise has access to it, — and that thQ effect if due to the 



COPPER. 39 

formation of caprons oxide, and its subsequent reduction by the charcoal, whereby car- 
bonic oxide is produced, and, endeavouring to escape as the melted metal is about to 
solidify, forms cayities within it^ and sometimes throws up the surface in vegetations. 
Copper, fused with free access of air and then cast in an atmosphejre of coal gas, 
exhibited the same cavernous structure, the specific gravity of two portions thus cast 
being only 6*926 and 6*438, whereas two portions of the same fused metal cast in air 
had the specific gravities 8*618 and 8*665. Again, copper fused and left to cool under 
charcoal had a specific gravity of 8*952; the same cast in coal-gas, 8*929, whereas another 
portion of the same cast in air had a specific gravity of only 6*193. 

Sulphur acts in the same manner as charcoal. The density of vesicular copper is 
greatly increased by hammering, but that of copper not possessing the vesicular struc- 
ture is but little increased even by very powerM pressure. Marchand and Scheerer 
found that the density of copper fused unaer common salt was increased by a pressure of 
300,000 Ibe. only from 8*921 to 8*930. 

The cubical expansion of copper by heat for 1° C. is 0*000061 (the volume at 0° C. 
being taken as unity), hence the linear expansion is 0*000017 (H. Kopp, Ann. Ch. 
Pharm. ItttiV l); according to Troughton, it is 0*000019188. 

Specific heat = 0*09515, between 0^ and lOO^C. (Regnault.) 

Copper melts more easily than gold, less easily than silver. According to Fouillet, 
therefore, its melting point is between 1000® and 1200® C. ; according to Ouyton- 
Morreau, it is 1207** C. (2204® F.) ; according to Daniell, 1398® C. (2538® F.). All these 
determinations of very high temperatures are liable to great uncertainty. It expands 
on solidifying. Copper containing red oxide melts at a lower temperature than pure 
copper, but does not form so thin a liquid ; it likewise solidifies more slowly. If the 
proportion of oxide is lareer, the paass does not expand in solidifying. The expansion^ 
is also prevented by an amnixfiure of 0*1 per cent, of potassium, zinc, or lead. Copper 
containing carbon behaves in the fused state like pure copper. 

Electric Conductivity. — Copper possesses great power of conducting heat and electricity, 
standing in this respect next to suver. Its electric conductivity has been studied with 
great care by Matthiessen and Holzmann (PhiL Trans. 1860, pt. i. ; see also 
Matthiessen, Proc Roy. Soc. xi. 126), who have examined particularly the eflfect 
produced upon it by the presence of foreign substances, a subject of great importance 
with reference to the use of copper wires for electro-telegraphy. The results are given 
in tiie following table : 

Electro-Conductivity of Copper, that of a hard-drawn Silver wire being =* 100. 

Wirtshard How Conducting Tempera- 

drawn, prepared. power. ture. C. 

1. Pure copper Protoxide reduced by hydrogen , . 93*00 at 18'6® 

2. „ Electrotype copper not melted . . 93*46 „ 20*2 

3. „ „ commercial „ . . 93*02 „ 18*4 

4. „ No. 3. After fusion in hydrogen . . 92*76 „ 19*3 

5. „ No. 3. Hydrogen passed tluough the) no aa if.e 
metal while melted . . . { ^^^^ " ^ 

Mean of the twelve determinations from which the^ gs-os 18*9 



preceding numbers were deduced . 



1 





Extremes obse 


rved . 


• . . • 


, 


, 


92*22 


II 


19*3 




and . 


• 




. 


. 


93*81 


»i 


19*7 




The 


conducting power 


was found to be increased 










about 2 per 














6. 


Coppex 


• containing red oxide, melted in contact iMrith air 


73*32 


II 


19*5 


7. 


i» 


It 


2*50 per cent of phosphonu 


1 . 




7*24 


»i 


17*6 


8. 


If 


II 


0*95 


II II 






23*24 


II 


22*1 


9. 


II 


It 


0*13 


II II 






67*67 


II 


200 


10. 


It 


II 


6*40 


„ arsenic 






6*18 


II 


16-8 


11. 


It 


It 


2*80 


II ti 






13*14 


II 


19*1 


12. 


ft 


II 


traces 


tt 1) 






57-80 


II 


19*7 


IS. 


ti 


alloyed with 3*20 


«inc 






56-98 


II 


10-3 


14. 


91 


It 


1-60 


It It 






76-35 


II 


15-8 


16. 


If 


n 


traces 


II II 






85*06 


II 


19-0 


16. 


If 


ti 


1*06 


„ iron 






26*95 


i» 


13-1 


17. 


ft 


ft 


0*48 


It >* 






34-56 


fi 


11*2 


18. 


If 


ti 


4*90 


tin 






19*47 


»» 


14-4 


19. 


ft 


ft 


2*52 


tt $t 






32*64 


If 


171 


20. 


ff 


ft 


1*33 


•• *> 






48*52 


If 


16-8 


21. 


n 


tf 


2*45 


„ silver 






79*38 




19*7 



COPFEIL 



with l-^pereenLof silrer 



t^ m 



3-^ „ 



^Id 



rj 



Ceoductliif 

power. 

. 86-91 &t 
. 65-36 ,, 



64-5 



2rn 

181 
12*0 



elt«d under > 



, from m dense ingot nielu» i«.««* r q, - .- 

Sil ITi»tW>»j|iii 0omp from s porroo* ingot of the same } g.^ . ^^ 

ttf^ ■siftd in the orduuiy w«j * . . { " ^ 

SI'. IThwlHiffjnii topper cemented with i^bnreoAl and con- } ^^ » . ^ 

iMri^dlieaiBadtmeMofpboflphDrtmaDdiroti. ( ^^ ^ *' ^^^ 
Dftto, ditto. . . , 63-2 „ 14-3 

Them rtnltM ahow that the electric conduetidtj of coppar is very greatly impaiied 
iffifli bf flBftll qns&tittes ci foreixo sulisUnces. The ooDducting power of perfeetly 
pawesCM b catimftted hr MutthieMen aa - 9G-4 at 13^ C. 

The wuMPil^ tnhle rKhibits the cooducting power of rarionB kinds of oommem&l 
«OMcr MM eoropftred with th«t of pure munolted electrotype copper, which is taken as 
Ibe sUikdAid. lod M eqnal to 100 at UQ'^ C. 

Wkrt Cufidueiliif T«iitper«tur« 

MMaMU power. C. 

L dpanish (Rio tinto), coutaining 2 per cent.j 

arsenic, bceides trncefl of leaOf iroD, ni eke), ( ^ '^'^'^ ^^ ^ ^ *^^ 
red oxide^ icc^ ..««,) 

2. Riiflsian, (Demidoff' s make), eontaining traces v 

of anenic, iron, nickel, red oxide of copper, f fi0*54 ,, 12'7 
&c. . . . . . • . : 1 

3. Tough-cake (make not sipccifled), containing » 

truces of lea<i nickel, untimonj, red O3dd«[-71'03 „ 17*3 
of copper, &;c. . * , * ' ♦ ; ' 

4. Best selected (make not specified), containing! 

traces of iron, nickel, antimony, red oxide J 81*35 „ 14 2 

of copper, &c. .,..,! 
0. Australian, Burra Burra, Traces of iron and J fig.gg , i .^ 

Ted oxide of copper only were foil ml . { ** 

6. Amerieiin, I^ake Superior, containing rracosv 

of in:>n and red oxide of copper, and OiJ3[ 82*57 ,. 16*0 

per cent, silver, . . . . J 

Fiufh/ ditfided copper. ^ Copper may be obtained in this state : 1, By reducing the 
carlxmate at a very f^entle heat in an atmosphere of liydrogen (Oaann. Pogg» Ann. 
lit* 406). 2, By boiung a coufentrated solution of sulphate of coppifr not eontaining: 
free acid, with distilled zinc. Aji »oon na the liquid loses ita colour, which it does in 
a short time, the ainc is romovedi and the copper powder well boiled with dilute 
Biilphurio acid, then washed uninterraptedly with water, pressed between bibuloos 
paper, and dried at 75^ C», or in a warm n^tort through the ttibulure of which a stream 
of hydrogen is passed (Botti^er, Ann. Ch. Pharm. xxxix. 172). 3. By i^L^itillg a 
mixtiiiv of 5 pts. cuprous chloride mid 6 dry cnrl}oniite of sodium with e^l-ammoniac, 
and aftcrwanis exh misting with water. (Wo hler and Liebig, Pogpr, Ann. xii 583). 
Copper thuu prepared is a 8oft» dark-red, dtill looking powder, which easily acquires 
the ordinary lustre of the metal by pressure, and if pressed together while red-hot 
welds together into a compact maas. 

Chtmicdl proptrtiea of Copper. 

Copper has much less afBnitr for oxygen than iron, and decomposes watear only at a 
bright red hr^at and to a small extent. In dry air it remains unaltered at ordinary 
tiHU^serutures, but oxidises rapidly at a red beat. In damp air it acquires a green 
coating of bseic carbonat^ and its oxidation is remarkably promoted by the presence 
of acidifi. The weaker acids, such as acetic acid, have no etfi?ct on copi^er, unlesa 
assisted hy the oxygen of the air, when the copper rapidly combines witli the oxygen 
and a salt of the acid is formed (see Ac«tatms of Coffer i 14), Copper Joes not 
dlasolTe in cold ht/drt>chl&ria a^id ; bnfc when boiled with that acid, especially in the 
finely divided »t-at«t, it dispUices hydrogen, and slowly dissolves as homichloride Cu*CL 
(Vogel, Sehw. J. xxxii, 301; Od'ling, Chera. Soc. Qo. J. ix. 291.) 

Nitric euid of ordinary atrength acts violently on copper, with copious srolution of 
nitric oxide and formation of cupric nitrate : 

4HN0* + Cu» ^ 3CuK0* + 2H'0 + NO, 




COPPER: ALLOYS. 41 

But tht strongest nitric acid (specific grayitv 1-62) does not act on copper, the metal 
when immersed in it remaining bright and quiescent ; probably the action begins in 
the manner just described, and an extromely thin film of nitrate is formed on the 
surface of the metal, which being insoluble in the strong acid, stops the further action. 
The same passive state is exhibited by other metals when immersed in strong nitric 
acid, espeaalJy by iron (q. v.) On diluting the acid with water, a Tiolent action is 
instantly set up. 

Nitro-muriatic acid dissolves copper with facility, forming cupric chloride. Copper 
is not attacked by dilute sulphuric acid, or even by strong sulphuric acid at common 
temperatures, but on applying heat, sulphurous anhydride is evolved and sulphate of 
copper is produced : 

2BPS0* + Cu» = S0« + 2H»0 + Cu«SO«. 
This at least is the principal reaction which takes place ; but a portion of the sulphuric 
acid suffers more complete decomposition, sulphur being deposited, part of which 
remains in the free state, while the rest unites with the copper as sulphideL. 

Copper likewise oxidises in alkaline and in saline solutions exposed to the air. In a 
dilute solution of ammonia exposed to the air, it is converted into cuprous oxide and 
dissolves. 

Copper in the state of foil or filings takes fire in chlorine gas at ordinary temperatures. 
At a rod heat, it unites directly with bromine, iodine, stdphur, selenium, silicium, and 
all the metals ; with mercury at ordinary temperatures. With carbon and with nitrogen 
it does not appear to unite directly, even at a red heat 

Compounds of Copper, 

Copper forms two classes of compounds, the Proto-compounds, or Cupric compounds, 
containing 1 at. of the metal united with 1 at. of a monatomic radicle, or 2 at. metal 
with 1 at. of a diatomic radicle ; e. g. CuCl, Cu(NO»), Cu'O, Cu«SO*; and Hemi-com- 
pounds, or Cuprous compounds (commonly called <£{-compounds), containing 2 at. 
copper with 1 at. of a monatomic radicle, or 4 at. copper with 1 at. of a diatomic 
radicle, e. g, Cu*Cl, Cu*0, &c. The cupric compounds may be supposed to contain 
the radicle Cupricum, Cu » 31*6 ; and the cuprous compounds, the radicle Cuprosum, 
Ccu s 73*2, their formuke then becoming CcuCl, Ccu'O, &c. There are also a few 
compounds containing copper united with electro-negative radicles in other proportions, 
e. g. a nitride, Cu*N, or perhaps Ccu'N. 

COPVBBf AXiXiOTS OF. Copper unites easily with most other metals. Many 
of the alloys were formerly stated to be chemical compounds formed in atomic pro- 
portions, but it is most probable that all of them (excepting those of copper and arsenic, 
which element occupies an intermediate place between metals and metalloids) are 
merely homogeneous mixtures. 

The presence of small (quantities of foreign metals, as arsenic, bismuth, zinc, iron, &c., 
in copper, produces considerable modification of its physical properties, for the most 
part impairing its malleability, tenacity, power of conducting heat and electricity, &c 

1. With Almnlniiim. (See i. 155). 

2. With Antimony. An alloy obtained by fusing the metals together in equal 
quantities is of a pale violet colour, very brittle, and of laminar structure. Accord- 
ing to Karsten, copper alloyed with 0*15 per cent, antimony is brittle when cold, and 
very brittle at a red heat, 

3. With Arsenic. An arsenide of copper, Cu'As, occurs native, as Domeykite, in 
the copper mines of Coquimbo and Copiajx) in Chili, and in some Cornish mines, in 
Teniform and botryoidal shapes, also massive and disseminated. Hardness, 3 to 3*5 ; 
lustre, metallic ; colour, tin-white, with slightly yellowish or iridiscent tarnish ; frac- 
ture, uneven. Specimens from Chile, analysed by Domeyko, gave : 1. From Calabaso, 
28-36 per cent. As, and 7164 Cu. 2. From Copiapo, 2329 As, 70-70 Cu, 052 Fe, and 
3-87 Sb 98*28. The formula Cu'Aa requires 28*3 As, and 7 1*7 Cu. The Cornish 
mineral Condurrite {q, v.) appears to be a mixture of Domeykite with red copper 
ore, arsenious acid, and arsenate of copper. 

Alloys of copper and arsenic may be formed by melting the two metals together, in 
which case, however, there is considerable loss of arsenic by volatilisation ; — or by 
heating copper with arsenious acid and charcoal, or other carbonaceous matter ; or by 
heating an arsenite or arsenate of copper with charcoal. The alloy called white 
copper, or white tombac, which hus nearly the composition Cu^As, is obtained 
in this manner. Percy {Metallurgy, i. 281) describes an experiment in which an 
intimate mixture of 500 grs. of copper, 1000 grs. of arsenious acid. 1000 g^. of 
carbonate of sodium, and 500 grs. starch, exposed to a strong red heat> yielded 
a hard, brittle aDoy, having a crystalline and dark bluish-grey fracture, melting 
before the blow-pipe below a red heat, and evolving copious arsenical fumes. It was 



42 



COPPER: ALLOYS. 



Ibiuid (0 eontuLD 34*1 per eent arBc^nie, which is rather more than the araoont indi- 
etttd bj thti lbnii&I& Cv*Am (662 Cu -i- 33*8 A^). Bert hi er ( Traiii dea Etttds par ia 
f^ Uokf, ii 410) defcribes ml alloy <»bt«med bj melting 1 pt of the tetzm^opric 
MMidde, Co^M with 4 ptfl. of copper, si semiHiiictile, reddi«b>gtey, with a slightly 
flbfooa Ihiotiije, and suiiceptibb of a flue polish. 

IHmr*9 arnenide, or TWnipmrmi, Co*Afl (analoBong to ITS*, PH', A*H% <«!;), ia 
pR»dloea bj paaaing arsenettea hydrogen gaa over 017 chloride of copper, or into a 
MlniioD of cnpirio sulphate z 

3CuCl + A»H* -^ Cu*A« + 8HCL 

It ii a black aubfltance. (K ace, Pogg. Ann. xliv. 471.) 

Copper alloyed with 01 5 per cent araenic, becomes §omewhat brittle when cold, 
and very brittle at a red heat. 

The ar«enidei of copper, fuaed with nitre in pi^r proportion, yield arsenate of 
potattinin and metalUc copper free ft-otn arsenic- Heated with oxide or anenate of 
copper, they give off arsenioua oride, and yield metallic copper. A mixtnxe of 10 pta, 
Chi^Aa and 6 pta. Cu*0 yields^ when heated, 10 9 pta. copper; and a rautave of 10^ 
Co^Aj with 6 pta, tetra-cupric arienate Chi*AsK)^ jielda about 9*2 pta. csopper, snpponiiff 
tba op«ntioil to ba performed in perfectly doacd Teasels. When the fiision ia enected 
in AH open enaeibU, part of the arsenie ia roasted by atmospheric oxidation^ and less 
oxide or nnicimie of copper is recjuired to render the me^ pore. (Berthier«) 

4. With Stamntli* The two metals imite at a temperatme betow the melting 
point of copper. An alloy of 1 pt. copper and 2 pta. biamnth begins to eipand a 
eonaidcrablo time after solidification (Marx, Sohw. J. Iriii. 470), Copper alloyed with 
small ^oontitieii of bismtith remains duftilo ot meim temperatures^ bnt when hammered 
becomsa so hard and brittle as to require a su>cond ignition^ and if the quantity of 
bismnth exoeods 0'6 per cent,, the alloy cmc^ks on the edm when hammered at a red 
heat (ITarsten). Eismutb 13 a frcquntit impurity in metaUic copper (n. 36). 

6, With Omdmlum* An alloy containing 54 '29 pts. copper and 4571 cadmium 
baa a light yellowish white colour, a fine^gmined »ea]y stmcturOt and is venr brittle. 
The cadmium Tolatiltsea completjely when the alloy is hejited to the melting point 
of copper. Etco a small quantity of cadmium renders copper brittle. (S tro mey e r.) 

«. With aoW, (See Goi.n.) 

7. With ZrtatvuD, (9ee lamruif.) 

&, With ZroB^ Combination butween copper and iron takes place with difflculty*— 
100 pt*«. of copper may be miidc to unite by fusion with any quantity of bar-iron from 

1 pt. to 100 anti upwiirds. The intensity of the copper colour increases till the quanti- 
ties of the two metols boramo equal; but the more the quantity of the iron exceeds that 
of the copper, the paler does the ftHoy become on the nactured surface. The alloy of 

2 ptfl, copper to 1 pt. iron has the greatest tenacity ; if the proportion of iron be in- 
ereotfed, the hardness increasea but the tenacity dtminishee, and the &acture then bo- 
eomes kminrir. From ores containing the sulphtdcs of iron and copper, the following 
alkyseont4iiniug different proportions of the two metals may be prepared. One alloy 
of this kind wm copper- red on the outer surfkee^ had ft pale uniform fracture, and was 
magnetic. Another exhibited externally a copper-red colour inclining to grvy\ had a 
deep copper-coloured and liiminated fracture, was magnetic, and intersperaod with 
isolated granules of copper and a few granules of iron. A third was iroii-colour**d, 
hard, hud a laminar fructure, was strongly magnetic, and exhibited isolated griitiules 
of copper and numerous granules of iron. (Mushet, PhiL Mag. [3] vl 81.) — Ac- 
oonlin^< to former statements, the alloy of copper and iron is ^y, sbghtly extensible, 
more diflicult to fuse than copper, and magnetic even when it contains only ^ pt. of 
iron. The britUenees of iron at a red hea t appears some times to proceed from admixture 
of copper. 

Carbon interferes with the combination of iron and popper. Copper impairs the 
quality of steel; and in the proportion of 2 per cent renders it brittle. (See Ibow, 
Ci^jftJtorr OF.) 

0, With &eatf . Tlie two metals fuse together at a strong red heat, but the mixture, 
onlftss cooled very rapidly, Bepurates into two alloys,'tho lower consist ing of cuprif*'roas 
lead, the upper of plumbiftiroua copper. By rapid c^xaling, an apparently horaogentHtua 
mixture may be obtained, hut on heating it a^aln, the compound containing the larger 
proportion of lead fuses out, wliile that which con t-ains the larger proportion of copper 
remains; this is tlie principle of the eliquation proccAs (p, 32). 

Small quantities of lesid dimiuiiih the ductility of copper, both at common tempera- 
titrea and *t a red heat. CopptT containing 01 percent, lead may Infused for ordmary 
purposes, but cannot be f^^mt^d into thin leaves or wires ; tliat which contains 03 per 
cent, lejid works better cold than hot, as in the latter caso it cnicks immediately nt the 
edges. (Kursten.) 



COPPER : ALLOYS. 



48 



Lead enters into the composition of many ancient bronzes, sometimes in large pro- 
portion ; see Tables B and D, pp. 45, 50. 

10. Witii XaniTAnMW* Keddish white, yeiy malleable, acquires a green tarnish 
bj exposure to the air. 

11. WithMeronry. See Mebcubt. 

12. With BKolybdenoin. Pale, copper-coloured alloy ; malleable if the molyb- 
denum is not in excess. 

13. With Vtokel. The alloys are very extensible, and incline to white in propor- 
tion to the quantity of nickel : 10 pts. copper with 1 pt. nickel form a pale copper-red 
alloy, perfectly ductile ; 10 pts. copper to 2 nickel, reddish white ; 10 copper to 3 nickel, 
almost white ; 10 copper to 4 nickel perfectly white, exhibiting on the touchstone the 
whiteness of silver. (Frick, Schw. xlviii. 114.) 

Old slags firom disused mines at Suhl contain white granules of metal, which are 
extracted and sold as Suhlian nickel silver (Suhler Weiss- Kupfer). According to 
Brandes, Schw. J. xxxix. 17), this alloy contains 88 per cent copper, 875 nickel, 
0*76 sulphur and antimony, and 1*75 iron, silicon, and aluminium. 

For tne alloys of copper, nickel, and zinc, see p. 51. 

14. With Platinaiii and the allied metals. (See those metals.) 

15. With Potasaiiun. According to Serullas, copper heated to redness with 
cream of tartar does not become alloyed with potassium. According to Karsten, copper 
thus treated takes up a quantity of potassium not exceeding 0*13 per cent, and is thereby 
rendered somewhat less ductile when hot 

16. With SUwer. See Silvsb. 

17. With Tin. The alloys of tin and copper are of great importance, constituting 
bronze, gun-metal, and bell-metaL The following details are taken fix)m Gmelin*8 
Handbook (v. 481). 

The arms of the ancients were sometimes made of bronze, an alloy formed of a 
large quantity of copper with a little tin. It is obtained by fusing the two metals 
together, generally in a reverberator^ furnace ; if the mixture is not stirred, two dis- 
tinct strata are apt to form, containing very different proportions of the constituent 
metals. The combmation of the metals in equal parts takes place without evolution of 
light and heat (Gehlen.) 

Tablb A. — Propertici of Alloys of Copper and Tin, according to Mallet (DingL 
polyt. J. Ixxxv. 378). 
1 at. copper =« 31*6, and 1 at. tin = 58*9. 



At.» 


Per 


GraT. 








Order 


Order of 


Order 


cent. 


Colour. 


Fracture. 


Tenacity. 


of ftlal. 


Hard- 


ofFusi. 


Cu. Sn. 


Cu. 








leabilUj. 


neu. 


bility. 


1:0 


100 


8-607 






24-6 


1 


10 


16 


a. 10 : 1 


84-29 


8-561 


r. y. 


>. gr.' 


161 


2 


8 


15 


b, 9:1 


82-81 


8-462 


r. y. 


f.gr. 


16-2 


3 


5 


14 


c. 8:1 


81-10 


8-459 


y. r. 


f.gr. 


17-7 


4 


4 


13 


d, 7:1 


78-97 


8-728 


y. r. 


V. c. 


13-6 


5 


3 


12 


e. 6:1 


76-29 


8-750 


pale r. 


V. 


9-7 


brittle 


2 


11 


/ 5:1 


72-80 


8-575 


pale r. 


c 


4-9 


brittle 


1 


10 


g. 4:1 


68-21 


8-400 


ash-gr. 


c. 


0-7 


friable 


6 


9 


1 3:1 


61-69 


8-539 


dark gr. 


lam. gr. 


0-5 


friable 


7 


8 


t . 2:1 


51-75 


8-416 


grey w. 


V. c. 


1-7 


brittle 


9 


7 


*. 1:1 


34-92 


8056 


whiter 


lam. gr. 


1-4 


brittle 


11 


6 


/. 1:2 


2115 


7•387^ 






' V. gr. 


3-9 


brittle 


12 


5 


m. 1: 3 


1517 


7-447 


stiU 




V. gr. 


31 


8 tough 


13 


4 


91. 1:4 


11-82 


7-472 


whiter 




V. lam. 


31 


6 tough 


14 


3 


0. 1:5 


9-68 


7-442 






earthy 


2-5 


7 


15 


2 


0: 1 





7-291 


• 


• 


2-7 


• 


16 


1 



In this table, r. under Colour, denotes red, y. yellow, gr. grey. Under Fracture, 
f. gr, denotes fine-grained, c. conchoidal, v. vitreous, lam, laminar. The numbers 
unoer Ttnacity, denote the weight in tons required to break a rod whose trans- 
verse section measures a square inch. The malleability was determined at 60<^ F, 
(15-6 C.) Under /TarrfwfM and Fusibility, the number 1 denotes the minimum, a, 5, 
and c are gun-metal ; d, is hard brass for pin-makers ; « to i are bell-metal ; k and l^ 
bell-metal for small bells ; m, n, and o, speculum-metal. (Mallet) 

• Th« " atoms »• In thit column and in the corresponding column of TaWe C (p. 47) roust be under, 
flood as merelir Indicating proportions ; the alloys are not definite compounds. 



44 COPPER: ALLOYS. 

a. Chopper, alloyed with a very small quantity of tin, becomes so hard and britUe 
when hammered cold, that it nM^aires to be again heated to fiill redness. (Karsten.) 

6. 32 pts. copper to 1 tin : resists the solvent action of hydrochloric acid mneh more 
completely than pure copper, and is therefore adapted for the sheathing of ships. 
(Mushet, PhU. Mag. [3] vi. 444.) 

e; 19 pts. copper to 1 tin : golden yellow, hard, malleable. 

d. From 8 to 11 pts. copper to 1 tin: yellow and slightly malleable: Gun-metal. 
The best proportion appears to be 9 pts. copper to 1 tin. The alloy of 11 pts. copper 
to 1 tin appears uniform after sudden cooling, to the unassisted sight; but when 
examined with a lens, it appears to be composed of striated faces of a reiddish alloy 
mixed with a white one. If it be still more rapidly solidified by pouring it into thick 
iron moulds, an alloy is obtained which appears pertectlj uniform, even under the lens. 
When quickly cooled in water after continued strong ignition, it remains uniform ; but 
if suffered to cool slowly after continued ignition, it becomes variable in composition, 
like that which has been slowly cooled after fusion. Hence the alloy which is uniform 
at the melting heat, and likewise at a strong red heat, separates into two different 
alloys when slowly cooled. The large mass of a cannon cannot be co<ded, even by 
moulds which conduct heat well, suddenly enough to prevent the formation of two 
distinct alloys, the one that is richer in copper solidifying first, while that which is 
richer in tin, containing 82*3 per cent copper to 17*7 tin, |»rtly rises to the top, and 
partly sinks into the mould. (Karsten, Schw. J. Ixv. 387.) 

e, 6*25 pts. copper to 1 tin : the densest of all the alloys ; its specific gravity is 8*87. 
(Briche.) 

/, From 4 to 6 pts. copper to 1 tin : Bell-metal. Yellowish-grey, and, when very 
slowly cooled from a red heat, very hard, difficult to file, sonorous, brittle, exhibiting 
a fine-grained fhicture. When heated to redness, and then suddenly cooled bv im- 
mersion in water, it becomes soft, and easy to file and turn, but may be haraened 
again by ignition and slow cooling. The Chinese cymbals called Gong-gongs are made 
of this alloy (D'Arcet, Gilb. Ann. Ivi 104 ; further Ann. Ch. Phys. Uv. 831). Bell- 
metal becomes malleable at a temperature not far below redness (Wollaston, Gilb. 
Ann. Ivi 106). — An alloy of 4 pts. copper and 1 tin fused, and then very slowly cooled, 
exhibits a striated surface, a dingy white close fracture, and is very brittle. When 
poured out into cold iron moulds, it exhibits the same properties ; but if immersed in 
cold water, after being kept for some time at a low red neat, it becomes yellowish- 
white and extensible. During the ignition, if somewhat too strong, white ^obules of 
an alloy richer in tin are seen to ooze out, but at a higher temperature, when the 
whole mass becomes liquid, they disappear. Hence the alloy appears to be resolved at a 
tem{>erature below its melting point, into two other compounds, which, on slow cooling 
reunite and form a brittle alloy, but remain separated if the cooling be more sudden. 

^. 8 pts. copper to 1 tin: reddish-white; very brittle; specific gravi^ 8*879 
laudet). With a small quantity of arsenic it forms a spectdum-metal, (Little.) 

A. 2 pts. copper to 1 tin : steel-grey, very hard. Kemains uniform, even after slow 
cooling from a state of ftision (Karsten). — 2 pts. copper, 1 tin, and ^ arsenic, form 
a speculum-metal; so likewise do 62 pts. copper, 33 tin, 2*5 arsenic, and 8 brass. 
(Little.) 

t. 1 pt copper to 1 tin : bluish- white, like zinc ; slightly malleable, not very hard ; 
specific gravity 8 '468 (C h a u d e t), 8 79 (B ri c h e). Remains uniform after slow as well 
as after sudden cooling. (Karsten.) 

k* 1 pt. copper to 2 tin: white ; brittle. Uniform, even after slow cooling. (Karsten.) 

/. 1 pt. copper to 3 tin : bluish white, exhibits a crystalline aspect and fibrous 
texture ; cracks under the hammer. Specific gravity 7*813. (Chaudet.) 

m. 1 pt. copper to 3*6 tin. In a tinned copper boiler, regular six-sided prisms were 
found to be formed, with indistinct cleavage parallel to p (Miller, PhiL Mag. [3] 
vi. 107). Yellow-greenish-white ; shining ; ductile ; of specific gravity 7*63 ; fusing 
at a red heat ; slowly attacked by dilute, easily by strong nitric' acid ; dissolves rapidly 
in boiling hydrochloric acid. (Gives by analysis 21-38 per cent copper, and 77*63 tin, 
which agrees nearly with the formula CuSn* (31 33 Cu and 78*67 Sn). (Roth, Pogg. 
Ann. xxxvi. 478.) 

n. I pt. copper to 10 tin : malleable to a certain extent, but cracks under the ham- 
mer; specific gravity 7*472. (Chaudet) 

Boiling hydrochloric acid extracts tin from these alloys, and leaves a compound 
containing a large quantity of copper with a small quantity of tin. (Chaudet Ann. 
Ch. Phys. vil 276.) 

The following table exhibits the composition of numerous bronzes, ancient and 
modem. Some of them contain larger quantities of rinc and lead than of tin, but 
they are placed here for the sake of comparison with the rest See also Table I> 
(p. 60). 



(d^a 



COPPER: ALLOYS. 



45 



Tablb B.—Componium of Bronze Coins, Weapons, Parts of Machinery, ^e. 



1, Old Attic ooia* 


Auifaotiir. 


1 


o 




s 


i 


1 




A.Mitscherlich 




gg-45 


1004 




1-05 




, 2. Atheoiim 


MilA. & Scbtnid 


. . 


76-41 


7-05 


, . 


16*54 






3. „ ^ ,- . ' 


K WagMi^r . 


, . 


83-62 


1085 


, ^ 


663 








0. Moofle 


, , 


87-96 


U-44| 








fi. Com of AlexaDder ^e 
















flold 


O^e&t. 


K ScbMid 


. ^ 


9596 


3*28 


. . 


076 




trace 




















Great, 


R. Wagpner , 


- , 


86-76 


10 24 




2-31 


. . 


ti 


' 7. Attic eoan 




. , 


a 7 89 


11'6S 




^ 


0-27 




8- »' » - - 


*i ' 


, , 


88-81 


9-61 




* 


1-18 




9. Of Aug. Domit. Cons. . 


« * 


. . 


S8-8 


I0'3 




0-9 






10. Jferra Tr^an. 


It * 


, , 


85-1 


115 




3-4 






IL M&rcos Autonlniu . 


It * 


Hi * 


84^ 


10*6 




4 6 






12. Muc, AurciL Commodijfi . 


It ^ 


, . 


89-5 


9*6 




0-9 






13. AI«(X&tidL^r iServrUB , 




. . 


S9-0 


10-2 




0-8 






14. PhiL Angtistiis 


TT » 


^ . 


88-8 


6-0 




3-2 






15. Eomwi Ab,B.C. 6O0* / 


Phillipf . . ; 


6*69 


69*69 


7-ie 




21-82 


0-47 




Id, Semif» B.C. 500 . 


II . . 


6-64 


6204 


7-66 




29-32 


0*18 




17. QoadnDfl, b.cl 600 , 


If ' ■ 


858 


72-22 


717 




10-56 


0-40 




IS, Hi«^, B.a47a 


11 ' * 


872 


94-15 


6-49 




, 


0*32 




19. Alev, the Gi^t, B.C. 33fi 


rl • * 


8-69 


86-77 


13-99 










20. Phnip Til of Macedon 


















B.C.323 , 


It • * 


S-71 


90-27 


9'4;i 










21, PhUip V, ac. 2CH} . 


li ■ ■ 


B'B9 


86-16 


11-1'i 




*Z'Bq 


0-42 




22. Atljeman (?) . 


II - * 


3-61 


83 34 


9-96 


» 


0-63 


026 




23. PtoletBjIX.B.a 70 


$t * * 


8-81, 


64-26 


15-64 


. 


. 


trB€<? 




24. Ponip«f, B,a £3 , 

26. Att.ilin family, B.C. 45 « 


19 • 


S-70 


74-17 


8-47 


, 


16*16 


0'28 




It 


B02 


68-89 


4-66 


. • 


26-43 


0-11 




26, Julioa und AnguatB*, 


















I1.C. 42 


It • • 1 


B-64 


79 13 


800 


. 


i2*ao 


tTare 






















B.CL 30 


ti * ■ 


865 


78-46 


12-96 




8-62 


tToce 




26, St SAmoaata , 


ft ' 


d'dtJ 


70-91 


676 




21*96 


" 


surer 


29. Vict€Tiiiti9^ 8«ii. 


i» 


8-77 


96-37 


0-99 




triicp 


n 


160 


30. 


fi . . 


873 


97-13 


010 




11 


im 


176 


31, Te^ii% Sen. , 


II 


. . 


98 60 


0-37 




ft 


0-46 


076 


32, „ ... 


It ■ ■ 


* . 


98-00 


0-50 






0-05 


1-15 


33. OandinB Gothicus . 


II " ■ 


8-61 


31-60 


7 41 




811 


• i 


166 


54. 


II . . 


8-71 


84-70 


S'Oi: 


trace 


2-67 


0*31 


7-03 


^. Todhu .... 


11 ■ ■ 


8-72 


86-08 


3'6;i| 




4-87 


« 


4*40 


36. ,, . . . 




8-7P 


91-46 


- 1 




, 


331 


6-92 


37, Ptobna .... 


Jt 


8-72 


90-68 


2-00 


1*30 


2-33 


0-61 


2-24 


38. „ . , , . 




8-74 


94-66 


n-46 




0-44 


0-60 


3-22 


3ff. Broken swcrad-bladB 


II . ■ 


^ , 


85-62 


10 02 




. 


0-44 




40. FragmeDt of sword'bkd^ 


II * 


■ ■ 


91-7B 


6-17 




. . 


trace 


8iill%har 


41. Broken spcar-beiul . 

42, Celt (Ireland) 


It • " 


. , 


99*71 


. 




» 


i^ 


26 


I* 


. . 


90-6R 


743 




1-28 


trace 




43. 


11 ■■ ■ 


. . 


90-18 


981 




. 


It 




U. „ - . 


ti ■ • 


' - 


89*3:^ 


9-lS 




. , 


0-33 


0*24 


45. n . • 


,1 . . 


' • 


83-61 


10'7B 




3-20 


058 


0*34 


46, Cerltie weapon" 


Freseniufl 


. ., 


92*00 


6-70 




0-60 0-29 


0'3l 



• J. pr. Chem. «1. 174. »• Chem. Soc. Qu. J. Itr. SM. 

c Otto Lerbb. d. anort. Chem. 3 Aufl. U. [SJ SIM. 



46 



COPPER: ALLOYS. 



Tablb B. (oontinned). 







AaihmHj. 


U 


■a 


i 


t 


i 




4T. Odtto Tesa<^ . . 


Clarke . 


8800' 


1200 








4S. Coffin ^m ih& Altai 


if m r 


80-27 


19-66 


' 








4&- 


Gobcl - 


73^00 


26*74; 










1 ^^- ^rptiaa dagger » 


Vauquelin 


S6'04» 


14-00 










SL G^o-Eomao axe , 


GiMrdin 


7777 


1961 


144 


1*18 






£2. Axe . . . . 


*i 


74-9 


2610 










63. ^medl stutaev foimd in 


KrdiBanD 


925S 


6-33 


» * 


» 


0*99 




6L 


the Olden- 


M 


80-41 


12-13 




1-00 


0-61 




66. Weapon 


burg difi- 


il 


91*90 


664 


, 


• 


044 




63. „ J 


trkt* 


li ' 


90-66, 


6*23 


. 


, 


0-26 




67. GalHc bcU- . , J 


Gii^rdln 


86-90 


U-10 


. 








53. EtrtiBcan Teasel 


If * ■ 


86-00 


14-20 


0*80 








09. Mij*mr * , , . 


fi 


78-50 


21*60 










60, liuckte «... 


ti 


37^0 


18*80 


» . 


44-00 


ti«oe 




6L HiBg , * , . 


*i • ■ 


4610 


U^OO 


» 


4000 




txacA 


62. Girdle-bucUe. 


1 


69-30 


20*60 


, . 


9-90 






63. Bticlile .... 


ft 


72*00 


, 


< 


28-00 






04, Bella of the 12tli contmy 


■f » » 


7610 


2230 


1^60 


tmee 


1*60 




1 66, 


11 


71-00 


2600 


1-80 


. . 


1*20 




66. Hoolcaof thelithcfrntoij 


IP 


71-90 


6-10 


* . 


27-9o: 






67. CMtic veflpen 


DoDOTan * 


66*23 


1341 


. M. 


1*14 






GB, ]>iiiikmg honi 


n 


79-34 


10-67 


. , 


9-1 1 






69, Brotue ring . 


Soirctat , 


76-65 


23-62 


. 


0*47, 






70. ., . . * 


n 


79-96 


16-63 


. . 


3-50 






71. Coltimn in the Place Voa- 
















dome' 


D'Arc^t * 


89-16 


10-24 


0-49 


010 






72- Ajtle-treobed of — 
















English locojiiotire* , 


KSdimid 


73*eo 


9*50 


9-00 


7-0 


0*42 




73. Belgiim ,» 


*i * * 


8000 


2-60 


7'80 


* 


0*80 




74. Soraiug ,, 

76. StuMng-box, Bel^an 




86*00 


14-t)n 










ir ■ 


9020 


3 50 


6-40 








76. FiAton of LoconsotiYe, 
















Semng 


II . ■ 


89-00 


2-40 


9-00 








7f. Heguktor, Belgian loco- 
















HiotiTe 


IJ ■ ' 


86-80 


12-40 










78. Stephenson'fl jotu^ala 




7900 


80 


6-80 


8-00 






7S. Pcnton*B „ 


If ■ * 


6-60 


U-6 


80-00 






AnttmQEif 


SO. Deomnee^'a ,, 


If « . 


22*22 


33-33 


^ 


* » 


. 


44-44 


61, Frictiooal bearing 


#i - 


80^00 


16-00 


. . 


_ , 


1 * 


2-00 1 


82, Canirusalon „ 


»J « 


7400 


3-70 


22*22 








66. BtaringB m hot sitimtiona 




66-00 


2-60 


6*00 


1*25 






61. Small ma«liine-whcel 


KocMin , 


90-00 


10-00 










86, Die for goM-vorkilig 




83-33 


16-66 








Blnaath 
0-6 


86, White tablo-gong , 


* . 1 


17 00 


80*00 










87. Chlaes^J gong^ 


Thijiii^on 


80-6 


19^5 










88. Tiim-t^ims* , , , , 


KLipzoth 


78*00 


22-00 










89. Speculum^ 


Otto 


65*16! 


3278 










90. French coin . 


Konig , 


96*00 


4-00 


I '00 




056 




91, OldbellatEoiiflai 


Gitamn 


71*0 


26-0 


1^8 


- ' 


1-2 





* J. pr. Chem. Ixxi. 331. 

• J. pr. Chcm. lx.9l. 

t Otto Lehrb. d. anorg. Chemie, 8 Aufl. il. fS] 255. 
ff Jahretb. <L Chem, 1A50. o. 687. 



1> Ann. Pbil. ii. 209. 

I lUndw. d. Chem. 2 Aufl. il. [3] 602. 

k Ann. Ch. Pbarm. cli. 66. 

1 Ann. Ch. Phyt. [S] 1. 205. 



COPPER: ALLOYS. 



47 



19. With Ziae (Gm. t. 477).-^The most important alloj of these metals is brass, 
which contains about 2 pts. by weight of copper to 1 pt. of zinc Other proportions 
form Tombac, Pinehbeck, Princes metal, Simtlor, Mannheim gold, Mosaic gold, &a 

The alloys are prepared : 1. By adding zinc to melted copper, or by fusing the metals 
together in a coverea crucible, the zinc being placed below, and the copper in fimall 
pieces at top. For brass, the proportion is 7 pts. copper to 3 pts. zinc Part of the 
zinc always bums away. The fusion is performed in crucibles, seven of which are 
usually placed in a circular air-fumacc — 2. By igniting copper in small pieces with 
zinc-oxide and charcoal or coal powder. In this older method of making brass, roasted 
native calamine or Aimace-calamine is ignited in covered crucibles with charcoal powder 
and copper, the latter being cut into small pieces or granulated. — 3. Copper exposed at a 
red heat to vapours of zinc is completely penetrated by them, but does not lose its form 
— Lyons Gold-lace is prepared by exposing rods of copper to the vapour of zinc till they 
are converted into brass on the surface, and then drawing them out into wire. A copper 
coin placed in a crucible above a mixture of zinc-oxide and charcoal, and moderately 
ignited, is converted into brass without obliteration of the device.— 4. By precipitation. 
Spurious gold-wire is prepared by boiling copper-wire (previously dean^ with nitric 
acid) with hydrochloric add, cream of tartar, and a mixture of 1 pt. zinc and 12 pts. 
mercury. When sulphate of copper dissolved in 20 pts. wat^r, is precipitated by zinc, 
the black flakes at first thrown down are an alloy of copper and zinc. 

Copper alloyed with a small quantity of zinc exhibits a paler red and yellowish-red 
colour ; a larger quantity renders it yellow, the colour being brightest when the two 
metals are united in equal parts ; a still greater quantity of zinc makes it white 
(Lewis). In certain proportions, the alloy of copper and zinc is more ductile at ordi- 
nary temperatures than pure copper, but generaUy brittle at a rod heat Very small 
quantities of zinc do not impair the ductility of copper at ordinary temperatures, ex- 
cepting that, when thus alloyed, it sooner becomes hard and brittle by hammering, and 
therefore requires to be oftener heated to redness ; but even 0*6 per cent, of zinc is 
sufficient to cause copper to crack when hammered at a red heat (Karsten). The 
most ductile of all the alloys of copper and zinc are those which contain 84*5per cent, 
of copper to 16-6 of zinc (tombac), and 71*6 copper to 28'6 zinc (brass). Tne alloy 
formed of equal weights of the two metals cracks in rolling* An excess of zinc renders 
the alloy brittle, the most brittle of all being that which contains 1 at copper to IJ 
to 2 at zinc (Karsten.) Small quantities of lead diminish the ductuity of the 
alloy ; tin increases its hardness. (Karsten.) 

4U aUoys in which the amount of zinc does not exceed 50 per cent, exhibit the 
reaction of copper towards adds and in the voltaic circuit, and they do not precipitate 
the salts of copper. But alloys containing excess of zinc decompose copper-salts, being 
thereby converted into perfectly pure copper ; they likewise dissolve completely in 
acids which have no action on copper alone, the solution taking place the more quickly 
as the excess of zinc is greater. If the quantity of acid is insiu&cient to dissolve the 
whole, the copper first dissolved is reprecipitated, the liquid at length retaining nothing 
but zinc (Karsten). Brass turns red when rubbed with hydrochloric acid, because 
the add dissolves the zinc in preference to the copper ; but when rubbed with am- 
monia, it turns white, because the ammonia dissolves out the copper. (Berzelius.) 

Table C. — Properties of AUoy$ of Copper and Zinc, according to M all e t (DingL polyt 

. J.1XXXV. 378). 





Per 










Order of 


Order of 


Order of 


At.« 


cent. 


Specific 


Colour. 


Fracture. 


Tenacity. 


Mallea. 


Hard- 


Fusi. 


Cn. Zn. 


Cu. 


grafltj. 








bility. 


ness. 


blllty. 


1 : 


100 


8-667 


r. 




24-6 


8 


22 


15 


10: 1 


90-72 


8-605 


r. y. 


c gr. 


12-1 


6 


21 


14 


9: 1 


98-80 


8-607 


r. y. 


f.gr. 


11-5 


4 


20 


13 


8: 1 


88-60 


8-633 


r. y. 


f.gr. 


12-8 


2 


19 


12 


7: 1 


87-30 


8-587 


r.y. 


f.gr. 


13-2 





18 


11 


6: 1 


85-40 


8-591 


y. r. 


f.f. 


111 


5 


17 


10 


6: 1 


8302 


8-415 


y. r. 


f. f. 


13-7 


11 


16 


9 


4: 1 


79-65 


8-448 


y. r. 


f. f. 


14-7 


7 


15 


8 


3: 1 


74-58 


8-397 


palo y. 
deep y. 


f. f. 


13-1 


10 


14 


7 


2: 1 


6618 


8-299 


f.f. 


12-5 


3 


23 


6 


1: 1 


49-4? 


8-230 


deep y. 
dark y. 


eg. 


9-2 


12 


12 


6 


1: 2 


32-85 


8-263 


cgr. 


19-3 


1 


10 


6 



• See Nole |». 48. 



48 



COPPEU: ALLOYS, 









Tabi^C. 


(condimed) 








^ 




Per 










Ora«F of 


Order o| Order dfl 


At. 


cent. 




Colour. 


Fracture* 


TeiMdtj. 


Mjiltea- 


H«ird- 


Fiiil- 


Cu. Zn, 


Cm. 








bfliir. 


ne*i. 


bllitf. 


8:17 


31-52 


7721 


fiilT. W, 


c 


2-1 


T, ht. 


5 


5 


8: 18 


30-36 


7-836 


Kllv. W. 


T» C 


2-2 


T.br. 


6 


6 


8: 19 


29-17 


7019 


light, gr. 


C. 


0-7 


V. br. 


7 


5 


8:20 


28-12 


7-603 


aah-gr. 


y. 


3-2 


br. 


3 


5 


1 8 : 21 


2710 


8058 


light gr. 


c 


0-9 


br. 


9 


5 


8 : 22 


26*24 


7^882 


light gr. 


c. 


08 


T.br. 


8 


6 


8:23 


2d'39 


7-443 1 


aah-gr* 


f.gr. 


6-9 


8. d. 


1 


5 


1 : 3 


24-50 


7*449 1 


ash'gr. 


f^gr. 


3^1 


V.hT. 


2 


4 


1 : 4 


196-5 


7-371 


aali-gr. 


f.gr. 


19 


br. 


4 


3 


1 : 5 


16 36 


6605 


dark gr* 


f-gr. 


1-8 


br. 


11 


2 


0: I 





6895 


• 




15'2 


• 


23 


1 



In this tablp, r under Cot&ur, denotefl rod, y. yellow, ffr, grey, sih. w. Bilrer- white, 
Undt^r Fracturey c.gr, d«*jiotcs coarae-mined, /. ^. fine-grainwU /. /. fine-fibred, r. con* 
choidalt t\ Titreous, lam. Jaminur. The iiumbors iinder Tenaciii/ denote the weight in 
tons required to break a rod whose tranarerae section meaaures a £>quare inch. Under 
MaUe4iMitUt br. Hignifiea brittle, v. br, very brittle, «. d. slightly dut^tUe ; the mallea- 
bility wftfl determiaed at 60^ F. (15-0 C), Under Bardness and FuaihU'Uy^ tke number 
1 denotes tbe minimum. 

The eompound {X>rrc«^nding in percentage compoeitioii to ZnCu^ is Prined* mettd^ 
or Btiih md4d ; ZnCu* la German and Dutch brass \ ZnCu* is rolled brafis ; ZaCu' 
is Englieh brass ; ZnOu is German brass ; Zn^Cu is German brass for watchmakers. 
(Mallet,) 

From experiments bj F, H. Storer {Memoirs of the Amirican Acadfiny^ NewSeriea, 
'^'iii. 97), it appeara that alloys of copper and zinc, formed by melting the two metals 
together in the most varied proportiouiii, theji leaving the mass to cot>l partially, and 
pouring out the still fiuid portioQ (as for the erystalEsatiou of bismuth, l 590), yield 
crystals of similar aspect, sometiinea exhibiting distinct octahedral faces, sometimes in 
eoufii»(?d aggregates of ciTstals, but all of octahedral cliaracter, and bearing a striking 
resemblance to tbe crystals of pure dipper obtained by fusion. From this resemblance, 
and from the obserrations of Nick lis (Jahresber, d. Chem. 1847 — 8, p. 434), that 
Rinc ciystallisefl in forms belonfdng to the regular system^ Storer concludes that idl 
the alloys of copper and zinc also CTYBtallise in that system, and are not definite 
atomic compounds, but merely isomorphoua mixtures of the two metals, — a eondosion 
furl her supjwrted by the fact that none of the crystals were found to contain a larger 
proportion of either metal than the remainder of the molten liquid from which they 
bad separated. The alloy containing from 6 to 6 per cent of zinc was found to crys- 
t alii «e particularly well ; the white alloys are difiScult to crystallise, having a great 
tendency to assume the pasty condition on cooling. Allays containing from 68 to 43 
per cent, copper are much inclined, especially when quickly cooled, to form fibrous 
aggppgatefl of crystals. The colours of the different alloys (on recently filed surfaces) 
exhibit a perfectly regular transition, without any sudden leaps, from the pure red oif 
copper to yellow, and ultimately to white. The purest yellow is exhibited by those 
oontaining from 75 to 80 ^er cent, copper. The hardness increases with the propor- 
tion of zinc. Sudden cooling in water renders the aUoys, for the most part, softer and 
less tenacious. 

Brasi — ^TMs alloy is harder than copjper, and therefore resists wear better It is very 
malleablis and ductile^ and may be raised by stamping into variotis objects, such as 
curtuin-bands. At a red heat, however, it is verj' brittle. It is well adapted for cast- 
ing, being easily fusible, and capable of receiving very delicate impressions from thfl 
mould. It is said to resist atmospheric influencee better than copper; but when 
its surface is unprotected by lacquer, it rapidly tamishea and becomes black. 

During the process of stamping braeia, that is^ of subjecting it to heavy blows in 
dies, as for the manufacture of curtain-bands, &e., the metal r^>quires to be annealfMi 
from time to time, and at the completion of the process tlie article p?maiiis discoloured 
by adhering oxide. This in removed by *' dipping" the metal in aqua fortis of suit- 
able strength, and then wasthing it with water. A bright metallic stirface is thus pro- 
duced, ready to receive the lacquer (a solntion of shellac in alcohol). The colour may 
be varied by using acid of diflForont strengths. 

The pale yellow dead snrfaco often seen on ornamental articles is produced >iy 




COPPER: ALLOYS. 



L'lu 



** pickling " the metal, after stamping, in weak aqtia fortis (say 1 pt. Btrong Dttric acid 
k» 7 or 8 pte. wat^r) ; then, after washing with wuter, immersiDg iJ: in much stronger 
-Bcid, tiU « white **cur(l/' due to a Btratum of email gus buhblea, forma on the surface; 
bgain washing with wat<*r j roughly drying the ohject by nioYing it about in cold satr- 
|4tU9t ; then dipping it again in strong nitric acid for a few seconds ; washing first in 
f water» then in a cold soltition of argol or impiim cream of tartar; and lastly diying in 
rhot sawdust. 

The surface of brasa is often coloured or bronzed after ** dipping" and before lac- 
quering. Thin is done by immersing tho orti-lo in a nolution of araenious acid in 
^hydrochloric acid, by applying a dilute aqueous e j^ution of chloride of platinum, or an 
laqneong solution of corroHivo anblimat« mixed with vinegar^ or by rubbing plumbago 
OTer the surfaco. Either of these applieationa prcniuccs a dark groy coating, wldcb 
asBiUEics a br%)nze-tint when Jacquered. Tho corrosive sublimate sobaion is nscd for 
oommoii work ; the platinum-proccsB for theodolites^ levels, and other instruments. 
{Ptrcifs MrtallurgjfJ) 

Munts's m^taL — Thia alloy and its application "for abeathing the bottoma of 

ahips, and other such Teasels," was tho aubject of a patjcnt granted to the iat^ 

G. r, Muntz of Birmingham^ in 1832. The proportions sp*?cially recommended in the 

spedficatioQ are 00 per cent copper and M\ zinc ■ but thfso proportions may be Taried 

from 60 up to 63 per centn and from fiO down to 37 per cent ^rnc?. Tho metal is caat 

.into ingots, and rolled ivhtle hot info aheeta, whicli, when finished, are •* pickled" in 

Vdilttte sulphuric acid, and afterwards washed in irateTi In the same year Mr. Mnntz 

l^btainod a second patent for **an improred manufactoie of bolts, and otiier the tike 

I for ships* fa-««t4*nings/* the same proportions ot copper and sine being used; nnd in 

1 1846, a third patent for the uj?e of an alloy consLStin^ of fi6 per cent, copper^ 431 zinc, 

"\^ lead. This last alloy does not appear to bavo been manufactured on a large 

but Dr. Percy states that ho baa aojooeeded in roUing brass well^ which con- 

i not leiks than 8 per cent of lead. 

Mtintz's metal, or yellow- metal sheathing, has entirely superseded copper ftheath- 

in the merchant sernce, though the latter is still Tctoined in the naiy. Its 

*al adrantaget are said to be that it keeps the bottoms of ships cleaner and 

much less than copper sheathing. It is now generally made in reverberatory 

__JCC8, the «nc being cautiously added to the melted copperj and the meltcil metal 

apped into a yesael lined with clay, out of which it is ladled into stiitablo cast iron 

igot-moulds. 

Mosaic *^o/c/,— Prepared by ftising eqnal weights of copper and sine in a crucible 
the lowest possible temperature, stirring constantly, and then adding a further 
rntity of sine in small portions, tiU the colour of tho fused mixture, after passing 
oagh the Tarious shades of brass-yeUow, purple-red, and violet, has become per- 
tly white. The alloy, after casting in the mould and cooling, exhibitja the colour 
! gold, and does not tarnish by exposure to the air, even in the neighbourhood of the 
^a. (Hamilton and Parker, Edink J. of Sc, 1826.) 
Brass soidrr. — 2 pta hraifl to 1 jdnc, or if it is to be more ductile, 6 pts. braaa^ 
\ sitTer, and 2 sine. 
Imitation hron£e^ Tomhw, Pinchbeck^ Princt*s trutal^ SmihTj Mattfihrim goid. — 
hese teims are applied to alloys of zinc and copper, containing 80 per cent or moi-e 
I copper ; also to alloys of copper with adnc, tin, and lead. The cheapness of zine 
laomiiarcd with tin,, has caused these alloys to bo exteuKiTely used of late years as sub- 
iitiites for truo bronie, which is an alloy of cop>per and tin,, espn-itdly for ornamental 
dei^ which are gilt or artifleially bronzed oq the surface. Alloys whoso composi- 

I ramgifl from 86 o per cent, cfjpper, 11 '6 zinc, and 4 tin, to 66 copper, 32 zinc, and 

! tin, may likewise be used for tho casting of statues^ as they run well into the mould, 

Ln4 ftre easily filed and chiselletL Those which approaeh to the latter compnsi- 

i£on, 66 per cent copper, &c., are too yellow to be used, excepting for objects which 

' to be gilt or artificially bronzed ; but the fiist-mcntioned alloy yield.'i a eiist of a 

deep red colour, which, by exposure to the air, slowly acfiuires a very beautiful 

The alloT called tombac, containing 84 -fi per cent, copper and 15'6 sine; is Tery duc- 
„ » sod nittilflable. Duick-metai \a tombac beaten out into leayea j^^ of an inch thiek. 
BfonJM^^oUmrg or Bromt'poitMiers, used for colouring objects cast m brass, imifation 
onae, or plastCT of Paris, and for various other ornamental purposesi, are prepared by 
•iturating Dutcli-metal or other alloys of copper and zinc, &c., between rtjUers with 
► and reisin, oil or fat. separating the fintr particles from the grosser by lorigation, 
- &e., and lastly drying and heating them. (See Ure'a Dictionary of ArU^ 
J jiciurei^ and Mines^ i. 463.) 
The Iblbwing Table exhibits the composition of various kinds of brass and imita- 
on-bronao. Sec also Nos. 72. 73. 75. 7G, 78, 79, and 82 of Table B, p. 46. 
Vol. ir. IB 



^^^^^^f JO COPPER : AXLOYS. ^^^^^| 




Tabi^ B. — CompofUion of mrious Alh^9 of C&pper and Zinc used in the ArU, 


1 




I, Brftsg, Engliah • . . * 


Aothority. 


1 


1 


i 


1 


i 




Latater* 


70-29 


29-26 


017 


0*28| 




2. Brass from H«>gcnnnlil 


»» 


7016 


274.5 


0*79 


0-20 






3. „ Angsborg ., 


♦1 


71'89' 


27*63 


086 










4. ,, Neiistadt, Eberswald . 


Kadcmatach* . 


71-36 


2815 












6. „ Eomilly . 


Chuudet* 


70-1 


29-9 












6, „ of unknown origin 


Karst4?ii * 


71^5 


28-6 












7, „ H . . 


Rcgnault* 


71*0 


27*6 


troce 


1-3 








e. „ „ . . 


Cbaudct* 


61-59 


35-33 


0-25 


2-86 








9. „ Stolberg . 


tr * * 


d6-8fl 


31*80 


0-25 


2-16 








10. Wtttch-wbeela .... 


Faisat* 


60-66 


36-88 


1-35 


4 * 


0-74 






11. „ , . • . 


»♦ • 


66'Ofi 


31*46 


1*43 


. . 


0*88 






12. Sbip-nailfi, bad .... 


Percy* . 


62-73 


4118 


1 


472 








13. ,. good. 


tt • • 


62-62 


24-64 


2-64 


8-69 








14, Tombac, Engli^^h 


Faiset' 


80'38 


13-61 


. ■ 


, 


tnee 






16, „ German 


Karaton* 


84-0 


15-5 












16. Coin of Titus Claudius 


Girardiii' 


81-4 


18'6 












17. „ Casaia family, b. c. 20 


















(sp. gr. 8-59) 


FhilHps* 


82-26 


17-31 


. 


* 


0-36 






Ift. „ NGro»A.D.60(Hp.gr. 8*501 
10. „ Titus, A. D.7& (ap.gr. 8-30) 


m 


81-07 


i7&r 


1*05 










l» 


83 04 


15-84 


. 


. . 


0-501 






20, „ Hadrian, A.D. 120 (sp. 


















gr.8'33) , • . 


11 * < 


85-87 


10-83 


1-14 


1-73 


0-74 






21. .. Faustina, jun., A.U. 165 


„ , , 


7&*16 


6 7 


4*97 


9-18 


0-23 






22. Antique bracelet^ Nauroburg 


Gobel* . 


8308 


15 38 


1-54 










23. „ fibula, Konigsberg 


»i • • 


82-5 


16 


1-5 










24. „ chain, Honneburg 


If • • 


82-5 


17'5 












26. Statu© of Louis XIV. {sp. gr. 


















8-482) 


D'Arc€t- 


91-45 


6*53 


1*70 


1*37 








2G, p, Henri IV. 


II • 


89-62 


670 


4*20 


0-48 








27. „ LoiiiaXV. 


»i * • 


82-45 


10-30 


4-10 










28. ,♦ Minerva in Paris 


ti 


831)0 


1400 


2-00 


1-00 








29. „ Napoleon . . 




75-00 


20-00 


3-00 


2 00 








30, „ Lessing, in Brunuwick 


Otto" . 


84*20 


11-50 


3*65 


0-75 








31. Bronze for gilding 


irArcet" 


82-00 


18-00 


2*50 










32. „ ... 


If . * 


64.60 


32-50 


0-25 










33. „ ... 


ti • 


82-00 


18*00 


3-00 










34. „ ... 


„ * . 


78^00 


18-00 


200 










35. Bronse .colour, palo yellow . 


Kunig* . 


8233 


16-69 












86. „ dwpycUow. 


,t * . 


84-50 


15-30 


. . 


. . 


0-ie 






87. ft red-yellow . 


f» • • 


90*00 


9*60 


1 


, 


0-07 






3S. „ orange 


fi * • 


08-93 


0-73 


. 


. 


0-2C 






39. „ copptT-rcd . 

40. „ Tiolet . 


11 • * 


99*90 


• • 


* 


* . 


0-0¥ 






t» • • 


08*22 


0*50 


trace 


. , 


tracfl 






41. „ green . 


Hi. 


84-32 


16-02 


TI 


, 


0'3{ 






42. „ whit43 . 


11 » • 


• - 


2-3a 


96*46 


. . 


O'OL 






• J. pr. Chero, Ht. l»«. h Hni. H»nittj. v. *7!>, 




^^^^^H H Fii«g. Ann. XKxr. i75, 1 H»Ddw. d. Chem. 3 AuB. IL [S] S<». 


^^^^H c Ana. Ch. Fhji. [2] f . 831, k Ch*m. Soc, Qu, J. W, 152. 


^^^^^^H d Om. Hjindt}. t, 4m. I Schw, J. Ix. 4{i7. 


^^^^^H * /f''^- n Handw. /oc. <rii. 


^^^^^H r Jabreib. d, Cb«ni., iBdO, p. 637. 


^^^^H Allocs cf Copv e r, Zine, and /r o n.— 80 pts. zinc, 1 pt copp^r» and 1 pt. casit iron 
^^^^^B form Sorel'R it'Aife dra^j. It ha» the aspect and fracture of ordinary zinc, is said to h*» 


^^^^H &fl hard as copper, and tougher tlmn cast iron, to aiimit of turning, fllinpr, and borintr, 


^^^^^P and not to riLst ov(^u in damp sitiutions, (Berthier, •t'ogg. Ann bLX. ^44.) 




COPPER ; BROMIDES. 




Alloy* t>f Copper^ Zine and "Nickel, — ywkd-siltvr, German-ailvcr^ White cop* 
pfr, Paf'kionrfar Pfwh/ong, Weisskupfer^ Neu-st'lbrr, Argent an, MaiUechort, — To prepare 
\\\i9 ttllriy, wMcli is macb used as a Bubstitute for i«ilvt?r, tho copper and nickd are iirst 
Tnelted in a crucible, and the kiuc i» then added in pieces previously heated. On the 
three metttlsit in a state of fine diVisiou, arc mixed together in a <mcible| eopper being 
placed ftt top and bottom, tho whole covered witia charcoal powder and heated in on 
air-furnace frith a Btrong drrtn^ht, tht* mixtare being Rtinvd all tho while, to ensure tho 
cumplete solution of the dijffi<juj!lly fusible tiifket The longer and the more completely 
the mixtare is fiised, the more duetilB do^s it become \ part of the linc buruii awaj* 
(Geradorfi; Pcwg. Aim. TiiL 103.) 

pT'oportions ofthe materials, — a, 2 pts, copper, 1 nickel, 1 zine : eervcB for spoons 
and forks, h. 5 pt«, copper, 2 nickel, % zinc : haa the colour of silver alioyed with 
i pt. copper; serves for knife aud fork handles^ snu^ers, &c, e. 3 pts, copper, 1 nickel^ 
1 xinc: this proportion gives the best alloy for rolhni*. The addition of 3 pt«. of lead 
to 100 ptfl. of the mixtLire a, or of 2 pts. It^ad to 10(1 pta. of the mixture 4 yiehls an 
alloy adapted for cast articles, such as candlestit^ks, spurs, and heUs. The addition 
of 2*5 pto. of iron oretecl to 100 pts, of alloy, renders it ranch whiter, but likewise 
haivler and more brittle; the iron must be previously fused with a portion of the 
cropper, under a layer of eharcoal-powder in the blast-furnace, and then melted together 
with tho E:inc antl nickel and tho rest of the copnor (Geraclorff). d. 8 pts. copper, 
3 nickel, and 5 zinc yield very good nickel-silver (Frick), An alloy of 10 pts. copper, 
1 nickol, and 6 zinc, has still a pale yellow colour ; that which contains 10 cop{>er, 
I nickel and 7 zinc, is yellowish-white and leas ductile than d!(Frick). Larger quanti- 
ti*'s of iron do not enter into oonibination with the nickel-silver as a whole, but unite 
with part of the copper, nickel, and carljotit forming an alloy which iloats like drops of 
oil on the snrface of the nickel-silver. (Erdman n.) 

Nidkel-Bilver has a crystalline Btrueture when 8<jlidifi«d from fusion. It must, there- 
foTie, be bcated to dull redness and cooled ag;iiiii completiily be;fore it is rolled or ham- 
mered ; when once the cryst^dline structure has been destroy^L^d,^ the alloy may be 
worked like brasa (Oersdorff). Chinese nickel -silvOT' may be worked even at a doll 
reti beat, but at a stronger heat it flies to pieces on the slightest stroke of the hammer 
{h^yi*^^ Edinb. Phil J. vii. 69). Nickel-silver is harder than silver, and suscepHble of 
a high p:>lish. Its colour approiiehes that of sDvcr* but is greyer. A mixture of 1 pt. 
cil of vitriol and 7 pts. water turns it wMte when boiled with it (Gersdorff). It is 
ot magnetic^ or bat slightly eo ; when it containi* a certain amount of iron. It fuses 
t a bright red heat, tho zinc burning away if th<? air has aeceas to it When exposed 
|to the air, it acquires a slight yellow tarnish. When immersed in vinegar, it becomes 
tfinated with verdigris, only at those parts where the air can likewise act upon it 
~^rick). In vinegar it becomMi greenish black ; in wine^ dark brown; in solution of 
non salt), red brown ; in solution of sal-ammoniac or tartaric acid, black with green 
I ; And in oxalic acid, black (D' Arc et, J* Pharmv iiiii. 223), In water contain- 

\ ^ of potash-hydrate^ it remains bright, (A. Vo g e I, ) 



An<dy$cs of C&mmercial 2fivkd-iilver. 



Fjfe. SmHb. O. Hearj. 



B*Arc«t* 



IVB 



13-6 



d. 
3125 



2r^ 



3*4 
188 
GOO 



trace 



19-3 
660 



lfi-75 
6000 



17 
2 

23 
65 



/ 
17'01 

traco 

1913 
63-34 



100-0 lOO'O 98-9 im-QQ 100 99 48 



Loiij«t. 

2215 

trace 

1505 
62-40 

90-60 



L 
26*05 

trace 

10*85 
62-63 

99-53 



BUaer. 

i, 

25-0 

30 

13^ 
57*4 

98-4 



fl, Chinese packfong, of specific gravity 8-432» k English nickel-silver, somewhat 
eilower than the German, c. Parisian Maillecbort ; contains also a trace of arsenic, 
jrhich remains behind when the alloy is disjwilved in nitric add, d and c. From un- 
known sources. / g, imd h. Engliah nickrl-aiker, nstnl in Birmingham for articles 
that are to be plated. *. From Sheffield, diiitinguiabed by cxtmordinary elasticity, 
tised for the frisketdi of printing-presses. 

American mckit'Si!wr,^\ pt. iron. I cobalt, 2 lUver, 2 tin, i mangjmese, 24 nickel» 

i sine, and 96 coppiT. (G m. v, 498,) 

COFFMS, asOBm»afl OIP* Copper dofia not unite with bromine at ordinaiy 
[ iempeni.tai>es, but on tho application of heat^ combination takes plac^ the chief pro- 
Ldoct being the hemibromide, Cu^Br. 

B 2 




52 



COPPER: CARBIDE— CHLORIDES* 



Prtftohromidsof Coppetf or Cupric Bromide^ CuBr, i» formed by evftfKiWi- 
ting the Bolution of cupric oxide in aqueous L^tlrobromic acid, and fufiing the peaidue 
at a gentle heat* The residiic is iron-black kke plnmbago. If the tioliitian bo left to 
evaporate tn racun over oU of Titrio], anhydioufi ahining crystab are obtained, resem- 
bling iodine in appeaxauco (Rammclflberg, Pogg. Aim. It. 246). According to Ber^ 
tbemotf protobromide of copper gires off haLTits bromine eTen below a red beat; ac- 
cording to BammEibberg, it mrm off 36-8 per cent and learea cuproua bromide, 

HifdraUd Protobr(miid€ (*/ mpper, or H^drobrometi^ ef cupric oxid^. — The emerald- 
green eolation of cupric bromide in water, or of cupric oxide in aqueoua bjdrobromie 
acid, or of copper in ^ mixture of hjdrobromic and nitric acidls, becomes brown on 
eTiiporatioti, and vitjldH rifiht reetangular prisms (^^reetiish-jeUow needlea, according to 
Bert heme t), whieli fuse at a [i^entlo heat, giving off their water and leaving a reaiduo 
of anhydrous protobromide of copper. 

Protobromide of copper and the hjdrated crystals deliquesce in the air^ and dJBHolTO 
readily in watery the green solution turns brown on evaporation, and likewise when 
mixed witb oil of vitriol or with salta, these enhstances depriving it of ita water 
(Lowig). Ammonia added to tbe solution in quantity not s^cient for eamplete 
precipitation, forms a palo green precipitate of hydra ted oxybiomide* 

AiMnmiiQ-citpriQ bromidts. — The compound iCoBr.SNH', is obtained by the action 
of dry ammonia gua on cupric bromide. It is a bluish powder, which, when heat«d, 
giTes off water iind bromide of ammonium. It diseolTea in a small quantity of water, 
forming a deep blue solution, which becomes turbid when diluted^ depoaiting hydratcd 
cupric oxide, which turns black when heated in the liquid (Ra mm elsberg, toc» eit.). 
Another amnion io-hromide, containing 2CuBr.3NH*, is obtained by mixing a strong 
solution of cupric bromide with a smfficicnt quantity of strong ammonia to form a clear 
solution, and then adding alcohoL It forms small dark-green crystals, but in other 
pesX^cta resembles the preceding. Eammelsberg found in the former of these com- 
pounds 28 '98 per cent., in the latter 19'2% per cent, ammonia. 

Hemibromide of Copper^ or Cuprous Bromide. Cu^r, or CcuiBr. IHhro- 
midc of ct/ppf^, — When bromin© is poured into tbe sealed end of a glasa tube, the 
upper part of the tulie filled with fine copper wire, and the copper heated to duE red* 
nesa, combination takes place, attended with virid incandescence. The protobromide 
which mixes with the mass is dissolved out by water. On disaolviBg the product in 
aqueous hydrobromic acid, any copper that may remain nn combined is left behind, 
and the cuprous bromide may be precipitatetl from the solution by water (Lowig). 
Another mode of ppc^paration is to heat thin rolled-up copper-foil in a flask, at tie 
bottom of whicli some bromine is placed, and when combination attended with ignj* 
tion is set up, to drop more bromine in, till the whole of the copper disappears. 
Cuproua bromide is likewise obtained by beating cupric bromide to redness. It is a 
dark-greenish brown mass, which is decomposwl by ignition, in contact with the air, is 
insoluLle in water, but dissolves without cniour in hydrobromic or hydrochloric acid. 
Nitric acid decomposes it, with evolution of nitric oxide. It is not acted on by sub 
phuric or acetic acid, even at the bjiling heat. It is said to dissolve in a<iue£»ua 
ammoniii, and to yield by cvaponitioa erj^stjils of an ammonio-bromide. (B er th emot) 

OOFPSSi. CAR8ISS OR C^&RSURST OF. Copper does not appear to form 
any definite compound with carbon. Pure (electrotype) copper may bo fused under 
charcoal fjowder without uii<letgoiag any change of physical properties. Ordinary 
copper thus treated becomes brittle at a red heat ; but the change is probably due to 
the presence of email quantities of forei^ metals, as in overpoled copper (p. 29). 
Whether any small quantity of carbon is taken up by the copper has not been exactly 
AlKertiiined. {Percy's MttaUurgy^ i 260.) 

OOFVIIK, €;a£0&I9Ed OF, fl. Protoehloridt of Copper, Cupric Chlo- 
ride, Chloridt of Cupric um, CuCL — This compound la obtained in tbe anhj* 
drouH state : 1. By the combustion of copper in chlorine-gas. Copper filings or copper 
tbil introduced into dry chlorine, takes tire apontaneoualv, and bums with a greenish 
light, produciBg a mixture of cupric and cuprous chlorides, and if the chlorine is in 
excess, the latter is slowly converted into cupric chloride. — 2, By heating the bydrated 
chloride to 200^ C. 

Anhydrous cupric chloride prepared by (1) forms a brown sublimate; by (2), a 
brownish-yellow powder. It has a caustic metallic taste, is fuaible, and at a red heat 
gives off half its chlorine, and is converted into the hemichloride. Heated in a 
current of phcsphoretitd hydrogen, it yields hydrochloric acid gas and tripbosphido 
of copper. Fused with pko^phonta, it forms chlorido of phosphorus and phosphide of 
copper (H. Rose. Pogg. Ann. xxvii. 117). It is not decomposed by s^Upkuric ankydride 
at or^linary temperature*! (H, Rose, ibid, xxxviii 121), Stdphurie actd does not 
decompose it at ordinary temperaturea, but completely when heated, hydrochloric 



COPPER: CHLORIDES. 



m 



Mcid being evolTed (A. Vogel), Heatwi in a cairent of etht^kne ffas^motochlonde of 

copper jitldB ft mixturo of copper and cuprous chloride (Wo ill or). When ea^o5ed to 

the aiff it turns green and dehqnesces. 

H^draiid pratocMoride of copper in produced: 1. By the delianeflcencc of the an- 
bli^drona chloride. — 2. When copper immeraed in hydrochloric acia is expos^ni to the 
I ftir for a considerable time.— 3. By diasolTing copper in aqna rcgiv — 4. By dissolving 
I enpric oxide or carbonate in hydrochloric acid. The aolntion of cupric oxide In concen- 
j trat«d hydrochloric iKjid is attended with great development of heat. — 6. By pouring 
I A stnidl quantity of water at 60° — 60° C. on a mixtnro of equal weighta of ptdreriBed 
Iptilniiate of eopper and eoinmon salt. The dark green liquid thua formed deposita, on 
IfiDoling, aryitala of sulphate of ^odiiim, and by farther evaporation the remainder of 
Ktitia aaltt together with the excess of chloride of Bodium : the decanted solutioi] finally 

fields OTitals of cupric chloride (Rieekher.) The emeirald-grean Bolution evapo- 

ated and cooled, yields ^een rigbt-anpled fonr-aided priams, which at lOO'^C. turn 
I Ikrown, giTing off the greater part of tbeir water, but do not part with the whole, 
[which amotints to 21 53 per cent., till they are heated lo 200*^ (Graham, Ann. Ch. 

Pharm. xxix. 31). Cold »ulpburic acid Hkowbe abstracts wuter from tbcm, and con- 
I Teita them into the brown anhydrous protochloridev which it does not dissolve or 

'eeompoae (A. Vogel). The cr^'atala deliquesce in the air. 
From the aqueous solufcioo, pho&pkorus throws down heraichloride of copper, and 
I Jbrms phosphoric acid (Boeck); the same precipitate is likewise |troduee<l by w*^- 
IcMr^Tf with formation of mercuroua chloride; by silver^ with form sit ion of chloride of 
IgilTer, black at first, but afterwards white (Wet alar, Schw. J. lii, 475) ; and by dU 
X^ofidt of tin ^ with formation of t^tracbloride of tin. Cuprous chloride is also preci- 
atated on ItoUing the aqueous Bolution with ttugar^ and partly remains dissolved in 
*" hTdrochloric acid produced by the reaction (A. Vogel); a solution of proto- 
iride of copper mixed with tthtr^ and exposed to the sun's rays, loses its colour, and 
Icm the adtUtion of water yields a precipitate of cuprous chloride. (Gehlen.) 
I The solution of protochloride of copper in a Hmall qnantity of water ib emerald-green, 
ilmt II larger quantity tnmfl it pale blue. The concentrated aolntion assnniea a yellow 
P^our on thii addition of strong hydrochloric acid. %Vith strong sulphuric acid, it 
Ipfytidifies to a brown mass. Characters traced ou paper ^4th the solution turn yellow 
I wbem heated, the writing disapfiearing as the paper cools. 
P^tochloride of copper is soluble in alcoltol and in ether » 
For tlie so-called basic cM^ridts ofc(^pper, sets Coffee, Oxtchxo hides of» 

Ammtmio^upric Chiondt4.^lOO pts. of drr cupric chloride quickly absorb 73'7 pts. 
I afnnu^nia, crumbling at the same time to a bluo powder. The resulting compound, 

k-which has the composition 3NH».CuCl, or possibly NHCn(NH*)'. CI, gives off part of 
Rita ammania on exposure to the air, and tnraa green. At 140^ C. it gives ofT 2 at. 
I smmonta, leaving an apple-green powder consisting of chloride of cuprmnmmiitmi, 
I KH*Cu.CL At a higher temperature, it gives ofT aiu-ammoniac and a small quantity 
[ nitrogen, and leaves cuprous chloride. (H. Bose.) 

I Tlie compound 3NH*.CuCl is obtained as a hycbate, 2(3NlI*.CuCl).H»0, by panaing 
[ ammonia-gas into a solution of cupric chloride. tiD the precipitate which iir?«t fcinns is 
Yiediseolv^ The liquid Ijecomes heated nearly to the boiling point, and on cooling 
Ldeposit£ the compound in dark blue prisms and octahedrons. (Kane.) 
I The di-ammonic compound is obtained^ by passing ammonia-gas in excess through a 
f Iiot saturated solution of cupric chloride, in dark blue hydrated octahedrons, which 
1 it 149® C. are reduced to NHVCuCl. 

Th e o^r^hioridet Cu»C10, likewise absorbs ammonia-gas, forming the compound 

\ Nir*Cu»cio, 

Protochioride of copper forms donble salts with the chlorides of the alkali-metals, 

Chiaridf of Cuprkum and Ammomnm (Kupfrr-jfotmak), Nn*ClCiiCl -t H^O, is ob- 

— Ahy dissolving 634 pt«. sal-ammoniac md 67'4 pt-s. iinhydrous or 85*4 pts. crjrs- 

d protochloride of eopper in a small quantity of water, and leaving the S43luiion 

ii^oL This salt forms bluish-green quadratic octahedrons perfectly soluble in water 

_iid alcahol, and easily decomposed by heat (M jtsohoriich, Graham) ; Henmann, 

1;^ the same mode of preparution, obtained a milt with 2 at water; so likewij^e did 

VHauta, by saturating hydrochloric acid with cupric carbonate, and mixing the solution 

Trith half the quantity of hydrochloric acid neutralised with ammonia* 

B^. ' ' lained several compounds of chloride of ammonium with biisic enprie 

(eilloT 1 rido ) by filling the bend of a IT-tuliC with claVj placing solution of nab 

|,jMnmo;^.» .u lUv one arm, cupric chloride in the other, and immersing the cud of a bent 

iptrip of copper in each ami in such a manner a» not by touch the clay. The end dip- 

'|>ing into Uie sal-ammoniac Ijecame covered in the course of a few months with 

crjrotals exhibiting njmarkahle truncations of tho angles and edges ; they were rssolTed 



64 



COPPER: CHLOEIDEa 



hy water into E*li]oride of ammoolum &nd. oxydilorLdo of copper. A simlliLr oompoimd 
waa obtained vnih cbloridt^ of potassium. 

Chloride of Cupnciim nnd Potastthtm, KCl-CuCl + H*0, is obtained in the same 
manner aa the corresponding amtnonium-salt, acconling to MitBcherlicli^ in Quadratic 
octahedrona, according to Jacq^ueLLiu, in double six-sided pyramidfi, liable in water 
and in alcohol 

HBittOKLOBiDi or CoppKK* Cuprous Chloridr, Chloride of Cuprosum. 
Ci^l or CcuQ^ ako called Dichioride of Copper, Bt*t/k's Ecsinu cupri. — Produced : 1. 
Together wilh the ppotochloride, by the combustion of copper in ciilorine gns. — 2. Copper 
heated witb protochlorid© of niercurj% yields rapour of mercury and hemichlorido of 
copper ( B o j 1 e ), Th o deeom poeitio a U\kcs phice most reodily mth 1 pi. copper to 2 pta* 
corrosive auMimate (J. Davy). More exactly, 6i ptfi. (2 at.) copper and 136 pis. (I at.) 
corrosive Bublimate. — 3. A plate of copper iniinen«ed in hydrochloric acid in a flask 
oon tainting aSr^ becomes co verted with white tetnihedrona of hcnuchloride of copper 
(Proust).— 4. The compound may also be formf^ by agitating copper-fihnga with a 
Bolution of the protochlorido in a dose vessel (Prouat).--6, B^ precipitating cupric 
oulphat^f hydrocnlorate, nitrate, or acetate with aqueous dichlonde of tin, or by treat- 
ing cnpric hydrate or carbonate with diehloride of tin dissolved in hydrochloric acid 
(Prouflt): 

4CuCl + SaCl« « 2Cii"'Cl + SnCl*. 

6. By treating aqueous prot^cbloride of copper with phoephonis, ether, sugar, &c — 
7* By heating the protochloride in a retort for a considerable time ; digest ing tho 
rcsstdne with water for seveml days with the retort closed, to dissolve out the unde* 
composed protochloride, and pouring off the resulting solution ■ the reyiduo consists of 
hemicblonde (Prouat). — 8. By agitating pnlverieed cuprous oxide with hydrochloric 
acid in a dote Teasel (Proust, Chenevix). 

Cuprous chloride, obtained by precipitation, is a w^ute crystalline powder, which ac- 
quires a dingy violet and blackish-blne tint by ex^ure to aunlight. It crystallises 
from its solution in hot concentrated hydro^ihloric acid in white tetrahedrons (Proas t), 
which turn bluish when exposed to li^lit. According to J. Davy, it separates in olive- 
gpn^D prisms. It melts aomewbat below a red heat, and when slowly cooled, solidifies 
m a translucent, light yt^llow mass ( greyish -white ; Proust) ; the residue obtained by 
rapid cooling is of a dark brown txilour, and confuted texlnre (J. Davy)* Specific 
gruvity of the melted mass = 3 '677 (Karsten), In close Teasels, it does not Yolali- 
liMe. even when strongly heated; but if heated in the air, it goes off in white Tapours. 

Heated to rednesa in a stream of htfdrt^ifm, it is converted into metal and nydro- 
chlorie acid gas ; in an atmosphero of phoftphft tiled Af/drt>^ai, it yiekls box cupric 
phosphide nnd hydrochJoric acid gas (H. Eose, Popg. Ann. iv. 110, 206), With irmi' 
jUitu/» under water^ it yiekla metallic copper and soluble protoxide of iron (Proust), 
^rrroua »idphatr added to the solution of the hemichloride in hydrochloric acid» 
throws down metallic (^opper (Pro us t), HemirJiloride of coppertums yellow when boiled 
with woter; but the decomposition is not complete {Prouat)» With fused ki/druU uf 
poiaMtnm or the aqueous solution of potash, it yields cuproiis oxide and chloride of 
potassium (Proust). When exposed to tho air in the dry state, it slowly attracts 
moisttiro and turns green j in tho moist state it is quickly converted into a green mass, 
(ProuBt)» With nitric acid it forms first a violet and then a blue solution, the 
action being attended with great rise of temperature and violent evolution of nitric 
oxide (Proust). A mixture of hemichloride of copper and sutphurie add assumes a 
faint violet colour when covered with a thin layer of fuming nitric acid. (Gmelin.) 

Hemichloride of copper docs not dissolve in water, or in dilute sulphuric acid ; but 
it dissolves without colour in strong hydrochloric acid, in aqueona ammonia, and in 
solution of common salt. A similar solution is formed by agitating the acid in a close 
ve^isel with cuprous oxide, or with a mixture of the protoxide and excess of metallic copper ; 
or by agitMing copper-filings with a fiolution of the protochloride strongly supersaturated 
with hydrochloric ucid ; or by mixing tlie sume solution withetherand exposing it to tho 
sun'w niys. The colourless liquid prt^pared hot, deposits erystxds of hemichloride of copper 
on cooling. The solution* when mixed with a considerable quantity of water, deposits 
the greater part of the hemichloride in the form of a white powder. Small quantities 
of ammonia added to the solution, produce tran*»pareot cubes of hemichloride of copper 
and ammonium, which dissolve in a larger quantity of ammonia, forming a colourless 
liquid which tums^blue on exposure to the air. Fuming nitric aeid imparts to the solu- 
tion a dark greenish-brown colour, which afterwards coEDges to yeUow with evolution 
of n itronH gas. (G m e 1 i n.) 

The hyilrocliloric acid solution of Iiemichlortde of copper imparta a blue colour to 
mohjbdic acid^ decolorL^es resyf ntly precipitsited Prmsinn Uut, throws down calomel from 
ft solution o{ ci^rrvsivfjfuhlifnakj and metiUlic ^^flW from a solution of goUL (Proust.) 




Wf COPPEU : DETECTION AND ESTIMATION. 55 

Aquioua eupr<ath0upric CMtrnde is formed in solution by oxposmg the aolufioTi pf 
1 cnppons oxido in ejccess of hydroeblorio acid to the air ; by mixing the saiDP solutioo 

with a solution of protochloride of copper ; or hj'- agit^Jting the laitMt initli a smiill 
I quantitj of copper-tilingB. It is u dark brown liquid. (Proust*) 
, Ammonio-cu^rout Chloride. — Hemichloride of copper forms a colour less solution with 

, ftqaeouB AmmoniiLi from wliicli potoab throws dowD cuprous hydrate^^ providod the am^ 
* monift is iu>t in too groat oxcess. 

I Chloride of Cu^osuni and Ammmtium. — The eolntion of cnprona cUoride in »tiong 

bydrochlofic acia mbtod with small quantities of ammonia^ tlf posits tmnnjmront 

t crystals which appear to be cubes (Gmclin). A similar compound in likewise formed 

when a solation of sal-ammoniac in whicli copper is immersed id exposed to the air. 

(Becquerel.) 

Chhride o/ Cuproaum and Poia^ttm^ 2KCLCcuCl, ia produced when cuprous chlo- 
ride, as obtained by mixing its hydrochloric acid solution with water, or tiy precipitating 
a cuprous tsJt with stannous chloride, is boiled with a small quantity of water, and 
mixi^i with chloride of potassium as long as the latt'er continues to dissolro. Tho 
solution on cooling deposits cubic crystals. Becquerel^ by tlio eleetpolytic mt^fhod do- 
scribed at page 53, obtained tetrahodral eiystals of the same or similar constitution ; 
also tile corresponding banumsaJt. 

Chltmde of Cuprosum and Sodium, — ^Cuproas chloride dissolTes rerr readily in 
solntion of common salt, and on cTaporating the liquid in vacuo, the double salt crjg- 
tallises out; with ditBfuIty, however^ on account of its great solubilify. Potash throws 
down cuprous oxide ; ferrocyanido of pntiisBinm yields a whit^? precipituto, 

COYP8«, DBTlSGTXOir ilJfl> I!8TmCA*nO»r or. L Reaciions in the 
2)rff Wetf. — Copper and iti< t'Oni|x>mids imp»irt a green colour to flamo. — Tho black 
oxi^e of copper dissolves by fusion in a vitreous flux, and produces a green ^laas. Any 
compound of copper fuj^ed with borax in the oxidising flamo of tho blowjupo forms a 
transparant glass, which is green whilo hot, but assumes a beautiful blue colour when 
cold. In the reducing fiame, the glass becomes opaqnCt and covered on the surfacQ 
with liver-coloured streaks of cuprous oxide, or metallic cop|>er, Thi« last reaction ia 
somewhat diflBcnlt to obtain* especially when the quantity of copper is small, but it 
may always be ensured by fusing a small piece of metallic tin in tho l>ead. Copper 
\ salts mixed with carlxjuate of sodium or cyanide of potoisaium, and heiited on charcoal 
before the blowpipe, yield metallic copper, Tho oxides, carbonatCH, nitrates, and 
ciigpuiic salts of copper are reduced on cliarcoal without the aid of an alkaline flux. 

2. Heactions in Solution, 

Of Cuprk salts, — Theto saltfl in Bolution have generally a sky-blue colour ; a 

~ solution of the chloride is green, but becomes blae on dilution with water. 

is separated in the matallic state from its salts by rhWf iron, kad, and the 

lire oxidable metals, which are dissolved and take the place of the former metal 

K) by ph&^tkorus from a solution of the sulphat4? or nitnite, and from a dilute 

■olutioQ of cupric chloride ; but in a strong solution of the latter, phosphonin first 

produces a white precipitiite of cuprous chloride, and then becomes lliickened from 

fbniuition of phosphide of copper. Wotid precipitates metallic copper from lU solu- 

tiona after long contact. Copper is likewise easily precipitated from its soltition by 

dednolysis, as in the electrotvpe process. 

SMipkifdrio acid and tdkafhw suipfudes throw down a brownish -black preeipitata 
turotoinilpbide of copper, inaolublo in sulphide of potassium or sodium^ slightly so- 
ible in oulpbtde of ammonium. 

PiotoMk OP aoda^ added to the solution of a cupric salt, throws down at first a light 
lAnt pncipitata of hydratcd cupric oxide, which, however, on agitation, takes up a 
porfioii of tbo undocomposed salt, and fomis with it a green basic salt. An excess of 
the alkali throws down the hydrate in bulky blue flakes, which, on boiling the mix- 
lurcy collect together in the form of a hiack powder, consisting of the anhydrous oxide. 
This reaction ui greatly modified by the presence of find organic 8uh»ttinc^s, such as 
sugar, tarUrie acid, &c. In a solution of sulphate of copper, containing such sub- 
stances in sufficient quantity, potash either produces no precipitate, or one wiiifh is 
f uieidj redissolved, forming a blue solution ; and from this solution, when boiled, ibe 
OOppor if aometimcB wholly precipitated as red or yoUow cuprous oxide, m when 
10 pnssent, or partially, as with cane-sugar, or not at all, as with tartarie 

, added by degrees, and with constant agitatiou, to the solution of a cnpri« 

it, first throws down a green basie salt, and afterward'^ the blue hydmte : an exceas 
\ aiumoDia dissoWes tho prt^cipitate, forming » deep blue solntion. A copper solution 
iluted so fttt as to be coIoutIc^hh, becomes dijslinctly blue on tho addition of ammonia. 




I tiona 
decb 



56 



COPPER: ESTIMATION, 



The lilao colour thui prodacf4 is still mible, according to Laaaaigne, in a solatiou 
cxintaining 1 pt of copper in 100,000 pU. of liquid 

Carbfmate af poiassivm or sodium throws down, with evolution of carbonic acid^ a 
greenisli-bliie pr«cipitato of a basic carbonate of copper, which, on boiling, is con- 
verted into the black ozida. Carbonate of a^nmonium producer the eame precipitator 
bat when udded in exci3«s, dissolrei it abundatitlj, forming a blue aolution. 

Cyanide of potoitaium cau&cfl a jellowiah ^reen precipitate of capric cyHnido, 
Boiuble in ezcese of the reagent : h jtlrochloric acid Ihrowa down white cuproiia cyanide 
from thii sohition, iolubk in exceaa of acid : enlphjdric acid, oraulpbide of amtnoniam^ 
produces no precipitate. 

FfTTvcanyide of potassium fornm with cnpric salta a deep chocolate-coloured preci- 
pitate of ferrocyanide of copper. To Teiy dilate solutions it imparta a reddiah colour, 
which is even more delicate in ita indications than the araiuonia reaction, being atill 
Tiaihle in a solution containing 1 pt. of copper in 400,000 pU. of liquid, aooordiDg to 
Laasaigne, and in 1,000,000 pta. according to Saxzeau* Ferrocjanide of copper dia- 
boXtos in aqueous ammonia, and reappears wheo the ammouia is crapomtea. Thia 
reaction Bexres to detect extremely small quantities of c<;>ppeT, eren when Baaodated 
irith other metak. Thus, if a solution coutsiining copper and iron be treated with 
cxceaa of ammonia, a few drops of feirocjanide of potaasium added, the liquid filtered, 
and the filtrate left to eTaoorate in a small white porcelain capdulc^ ferrocryanide of 
copper wiU bo left bebino, exhibiting ita cbaiacteriatic red colour {Warington, 
Chem. 8oc Qu, J. t. 137). Iodide of potassium added to cnprie salts forma a jellow 
precipitate of cuprous iodide, with separation of iodine. Cupric salts arc completely 
reduced to cuprous salts by alkahne sidphitcs, partially by free aulphurous acii 
H^posiiiphiks, at the iKjiling beat, throw down sulphide of copper. 

fl. 0/ Cuprous salts.-^Bnt few of these ealta are capable of existing in solution. 
Cuprous oxide is decompoecd by n on -oxidising acids, such as sulphuric, pho^pborJc, 
oxalic, acetic, and oven by dilute nitric acid, into metaUic copper and a cupric aalt, 
and ia oxidised by strong nitric acid, yielding cupric nitrate. Hydrochloric acid 
added in small quantity to cuprous oxide concerts it into white cuprous chloride, 
which dissolves in a larger quantity of the strong acid, forming a solution which is 
colourless if quite pure, but generally has a brown tint> due to the presence of a small 
quantity of anhydrous cupric chloride ; on exposure to the air, it gradually tuma green. 
The colourless or brownish solution exhibits the following iieactiona : — 

Wattr added in aufficicnt quantity tfirowa down a white precipitate of cttprom 
chloride, tliis compound being soluble only in stronpf hydrochloric acid» 

Cawfde potashf added in small quantity, neutralises the j^e acid, and pre<^pitat<4 
the white cuprous chloride ; in larger quantity it forms a browniah-yellow precipitate of 
euprons hydnite, insoluble in excess of potash, soluble in a large quantity of ammonia ; 
when expoaed to the air, it gmdually turns bladk. 

Ammonia in exceaa forms a colourless aolution, which gradually turns blue on expo- 
iiire. Potash added to this ammoniacal aolution throws down the browniah -yellow 
hydrate, provided the quiintity of amnionia present is not very lai^e in pro|K>rtion to the 
potash. Carbonate of ammonium acta in. like manner* 

The carhonatfSt both neutral and acid, of poiasmi7n and sodium farm a yellow pre- 
dpitate of cuprous carbonate. 

Iodide of poiamum forma a white precipitate of cuprona iodide, without liberation 
of iodine. 

Sulph^dric acid produces a black precipitate of ciiprous sulphide. AfkatimB 
sulphides produce the same precipitate in aolutiona preriously saturated with 
ammonia. 

Zinc and trort precipitate metallic copper. 

Cujiroua solutions are formed by treatinp^ the solutions of rupric salta with alkaline 
Bulphitca. Free sulphurous acid produces but a partial dooxidation and divoloration, 
©yen after prolongetl boiling, the product formed being a cuproso-cupric sulphate, 
which sometimes separates in rwl crystals ; butif potawh or ammonia be likewise added, 
the solution becomes quit© colourlesn even in the cold, and contains a double sulphate 
of cuproKum and the alkali- luetaL This colourless solution behaves with ammonia, 
and toe other reagenta above mentioned, in the same manner as the solution of cuprous 
chloride in hydrochloric acid (excepting that it is not decomposed by dilution), and 
jielda with cyanide of pCftaMium a white precipitate of cuprous cyanide, which dis- 
aotrea in excess of the reagent, forming a solution which is not precipitated by sul- 
phide of ammoniuiEL 

Cupmua a&lta, especiaUj the solution of the chloride in hydrochloric acid, quickly 
absorb mrbonic oxide gas. The solution of the chloride aatujuted with this gaa is not 
precipitated by water, or even by alcohol (L eh lane) 

M*ir»h-gas ia likewise absorbed by the soluf ion of cuprous chloride. 



COPPER: ESTIMATION. 



«r 



3. Quantitative Estiinaiion. 

When eopp«r is dissoWed in nitric acid, find the solutiOB does not contain an^ 
other metal or non-Tolatile jsnbst&ncei, it is Huffieient to evaporate tbo soJulton to 
diynesa in a platinum or porceliun crucible, adding a Blight eieeaa of nitric acid to 
pNfveot reduction of tha copper by anj^ deoxidising substance tliat may be present, and 
neftt tlie reaidua to redness. The copper then remaina as protoxide, which mtist bo 
weighed tmmediatd.y aft^r cooling, with the corar on the crucible, bocause it is very 
hyeroaeopic : 100 pta. of tho oxide ooirespond to 7^*82 per cent, of copper. 

Id other cases the copper miiitt be separated by precipitation. This may he done 
in aerv^ vaya, 

a. Jiy cattAtic poiaahf which, when added to a boiling solution of a cupric salt, throwg 
down tne copper aa protoxide, in the form of a heavy black powder. Care muat bo 
takcD not to add the potujsh in too great excess, as a small quantity of tlie copper will 
then be retained in Bolution* The precipitate is to be washed with boiJing water, 
then dried on the filter, ignited in a porcelain or platinum crucible, and weighed with 
the same precautiona as before. As a sinaE quantity of the protojdde may have been 
reduced by the organic matter of the filter^ it is beat, after weighiBg, to moiaton it 
with a few drope of nitric acid, then ignite and weigh again. 

A, Htfpochloride cf sodium may, in aome cases, be advantageously ust*d in place of 
caustic alkalis, to precipitate copper m protoxide* (Field, Chem. Hoc. J, xiv. 159.) 

c. When other metals ore present, it is often necessary to precipitate the copper as 
sulphide, by Mu/phydrw acid. In tliiti case the precipitated sulphide must be washed 
as quickly as jK>8sible with wat^r containing suJphydnc acid, to prevent oxidation* The 
precipitate may then h& dried, and tho filter burnt with the procipitatc on it, afUsr 
which the precipitate is treated with strong nitric acid, which dissolves it, with Hepa- 
ration of sulphur, and the copper is precipitated from the solution by potjiish as abovi?. 
The chief precautioQ to he attended to in this process, is to wash the precipitated sul- 
phide qniiily, and to preserve it an completely as possible from contact with the air, 
othervnse the sulphide becomes partially oxidii?ed and converted into sulphate, which, 
beii^ soluble, runs through the filter; when this takca place, the filtrate becomes brown, 
because the copper thus carried through is again precipitated by the sulphydric add 
in tho filtered Jiqnid, 

From neutral or alkaline solutions, copper may also be precipitated by sulpkidt of 
Qmmonmmt but this method ia not quite so exact, bdcansfi sulphide of copper ia slightly 
soluble in that reagent, and the precipitate oxidises more quickly than that formed by 
sulphydric acid. 

a. By line or iroft, A Tery exact mode of estimating copper is to precipitate it from 
its solutions in the metallic state by means of pure zinc. The solution, which mar a)ii- 
taio sulphuric or hydcochloric acid, but should bo ^e &om nitric acid, ia placed in n 
platinum capsule or crucible, previously weighed * a piece of £LDC large enough to pre^ 
cipitate all tlie copper is immersed in it ; and if the solution is neutral, hydrochloric 
acid is added in auiiicient quantity to produce a moderately brisk disengagement of 
hydrogen, the Teasel being covered with a wateh-frlass, to prevent splashing. Tho 
copper is immediately precipitated, partly on the platinum in a compact Iftyer, portly in 
the spon^ form. As soon as all the zinc appears to he dissolved, the precipitate must 
hs pressed La different parts with a glass rod, to make sure that there are no little 
lamps of line remaining j the complete solution of tlie zinc may l>e insured by adding 
a f^w drops of hydrochloric acid, and observing whether any fiirther evolution of hy- 
drogen takes place. The dear solution is now to be decanted, and a drop of it tested 
for eopper with ferroeyanide of potassium: if no coloration takes place, the precipitated 
eopper may be washed witli hot water by decantation, till tho wash-wat^tr no longer 
gives a cloud with nitrate of silver; the greater part of the water in the cmeible is 
then poured ofli as much as possible of the remamaer taken up by filter- pa p<'r, and tho 
predpitnted eopper dried as rapidly as possible at 100^ C, Chen left to eool and weighed. 
The precipitation may also be performed in a glass or porcelain vessel, but it is not so 
raptcl as in platinum ; it might, however, be accelerated by inserting a piece of plati- 
num foil. 

This process givea veir exact results, provided the zinc used is perfectly pure t if, 
on tlie other hand, the xinc contains lead, or any other metaJ that will not dissolve in 
hydnx!hloric acid, that metali^'ill mix with the predpitated copper and vitiate the re- 
sult. It is nvcessury also to avoid using a piece of zinc much larger than is necessary, 
as in that case, after all tlie copper is precipitated, an electric circuit may be formed 
between this copper and tlie remaining zinc, which may cause a small portion of the 
diisolred zinc to be depositctl on the copper in the metallic stnfce, and to mix itself 
•0 intlQUitely thert^with, as to rendt^r its subsequent separation by hydrochloric acid 
p difficult. (IT, Rose, Ckinm Awi^ftiqm, ii. 267.) 



58 



COPPER: ESTIMATION. 



Iron IB not 8o ^?ood b precipitimt aa zinc, becaaae it always contains earl>on, which 
remain** undissolved and iiicreiises the wei^bt of the precipitated copper (lioee). 
Mopyover> tiule«8 a certaiii ejuseas of hy^lrochiotic add is pneaejit, ba*icj a&iU of ii\)n 
lire suro to ho formed^ which renmiuwith the copper and increase its weigbt; and, on 
the other hund, if much freo hydrochloric ucid la present^ u portion of tho precipitated 
copper is likelj to bo dissolved in tko form of cuprous chlorida (Field, Chemical 
News, i- 62.) 

tf. Other modes of prcoipitatiim.^-ThQ following methods have been recommended, 
but thoir resiilta are, on the whole, not to he depended upon bo much us those of the 
methods previously given, o. By sulpkm^anate of pot4issium, in b neutral or slightly 
m'idulated solution of coppt*r, previously treated with an allcEline sulphite, to reduce 
the cupric salt to a cuprous salt. The precipitate, after being left to settle, is collected 
on a weighed filtflr, washed, dried at lOO*^ C, and weigli«d, the copper being calcu- 
lated from the weight of the cuprous Fulphocyanatej CcuCNS, which contains, 52*5 per 
oeui. copp*>r (Ri vo t). According to Rose, the method u? not quite exacts bc'cause the 
Bulphocyanate of copper is slightly soluble in water, ^. By boiling the cupric solution 
with hyposulphiie of sodium. The co[>per ia then completely precipitateti as 8ulphidt% 
provided the qu&ntitj of the reagent added be only just what is re<]uire<lj but an 
excess retains a portion of the copper in solution as cuprooo-pot^issic hyposulphite. 
The method is therefore very nncertftin. 7. By iodids 0/ potassium, which thrttws 
down cuprous iodide ; but the precipitation is never complete. 8. By introdueing a 
weighed piece of met^lic copper into a solution of a cuprie salt supersaturated with 
ammonm, and diluted with do-aerut'cdwater.soajs tocompletely fill the coutaiuingYesst-l, 
which is then tightly closed. A quantity of copper is thereby dissolved jast sufficient 
t^ convert the euprie oxide, Cu'*0, in the solution into cuprous oxide^ Cu*0, ^that 
is to s&jf a qiiaiit]^ equal to that which preTionslj existed in the solution. Henci5^ 
if the copper plate be weighed after the reacdon is complete, the loss of weight gives 
the quantity of copper in the original solution. This method, given hy Levol, is a 
modification of Fu ch s ' s method of ent linating sesquioxide of iron, {See Iiiox, J^stima- 
TtOK OF.) According to H. Rose {Chimie Analytique, ii. 259), the quantity of copper 
winch it gives is always too large. 

When copper exists in solution, in the form of a cuprous salt, it may bo oxidised 
by nitric acid, and then precipitated by either of the methods above given- 

* If a solution of copper contains organic mattcr» hut no fixed inorganic suhstAnce, it 
may be evaporated to dryness, then calcined in a current of air, to bum off th« or^Tanic 
matter and oxidise the copper, which may then he moiattiued with a drtip of nitric iurid, 
ignited^ and weighed ; or the oi^nic matter may bo destroyed by eitlier of the pro- 
cesaea given in connection with arsenic (L 366). 

FoZwmdw Methods of estimating Copper, 

ParktSfS method, by cyanide of potassium {Mining Journal^ 1861)l— Wliea s 
solution of cyanide of potosi^ium is slowly a<lded to a blue ammoniftcal solution of 
copper, the colour gradually becomes fainter and ultimately yanishes, in consequmco 
of the formation of capro-cyanide of ammonium. The reaction is complicated, several 
double cyanides of copper and ammonium being formed at flret, but, according to 
Mohr, the ultiniiite result is the formation of the compound CuCy.NH*Cy, contaiuiug 
2 ut. cyanogen to 1 at. copper. On this supposition, each atom of copper (316 gf«.) 
in the solution will requh^ 2 at. cyanide of potassium (2x65= £30 gr«. ) to precipitate it. 

To standardise the solution of cyan id© of potassium, a kno^ii weight (5 to 10 grs.) 
of pure electro tj-^M* copper is difis<:tlved in nitric acid, the solution boiled to expel nitrous 
fumes, then diluted with water to alxiut half a piut^ and treated with ammonia in 
excess I and to the re&ulting blue hquid, the st^ution of cyanide of potassium is gra- 
dually added frtjm the burette, till the deep blue colour is ahno^ discharged and is 
replaced by a faint lihic tint. It is then left to stand for about twenty minutes, and if 
the colour does not complet^lv diHappcar, a little more of the cyanide solution muat be 
added from the burette, ana the liquid again left to stand till the colour has disap- 
peared. The number of burette divisions of the cyanide solution added will give the 
value in copper of a grain-measure (or of b cubic centimetre) of the solution. Thus^ 
suppose that 200 divisions of the burette are equal to 1000 grain measures, and that 
147-5 divisions of the solution are roquii^d to decolorise a solution conUining 7-5 grains 

of copper; then 200 sucli divisions would decolorise a solution of " ,J5 » 10' 17 

147'5 
grains of copper. Ey repeating this dclermi nation two or three times with diiferent 
quantities of coppr, the mean value of 200 burette divisions may be found. It is 
convenient to dilute the solution, so that 200 burette divisions shall coor^spond 
exactly to 10 grains of copper. 



COPPER: ESTIMATION. 



10 



The stmidard eolution of cyanide thus obt&Inod is to h& applied in exiietly tbe same 
manner, to estimate the uinount of copp+?r in unj given w^lutioa. Tbus^ suppoaa 
37 gra. of a eoffpcr-ttlloy to be dissolved in nitric acid, and thul iJie soluhion tje^iled 
witi excess of ammonia is dc<:olorJ&ed, os above, by 320 burette divisions of tbe 
ttandard cyanide aolation » tbeu the quantity of copper in the 37 grs. of alloy ia 

;^--* 10 = 16 gre., and the pepceotage of copper is— -100 = 43 2 per cent. 

This method i« Tejy e3ctensively used for the assaying of copper ores. When caro- 
fally performed, it will pive the amount of copper correctly withiu 0*1 or 02 pt^r cent. 
It hafl also th© great advantage of not being vitiated by tlie presence of iron in tbo 
volution. Wlien this metal is present^ the cyanide-solution should be added to the 
ammoniacal liquid without jUtering <jff the auspfjidid ferrw oxide; for this oxide holds 
an ammoniacal solution of copper with such tenacity, that it cannot be completely 
acparated, even by severul hours washing with boiling wuter. The method may also 
be applied to the estimation of copper alloys and minerals containing tin, antimony^ or 
arsenic, but not to such as contain zinc, nickel, cobalt, raanganescv or silver^ because 
\ tiiese metals likewise form double cyanides. (Fields Chemical NewB» i. 25.) 

Pelourt'^n mat hod, by sulphide of sodium. — The copper being dissolved in an 
•cid, the ftolntion is treated with excess of ammonia ; and to the deep l>1ue solution 
thus formed a solution of sulpliide of sodium, of definite strentrth, is added. The 
copper is thereby precipitated in the form of an oxysulphide, Cu'0.6Cu'8, liy addinjCj 
the alkaline sulphide cautiomiiy, it is easy to catch the precise moment when all iho 
cof^>er is precipitated, because the liquid at the same time becomes colourless. The 
' quantity of the solution of the alkaline sulphide usod indicates the q^uantity of copper 
present 

The exactness of this method is not diminished by the presence of iron, zinc, cad- 
jnitim, tin, lead, or antimony, because the sulphide of sodium docs not begin to act on 
these metals till the copper is completely precipitated ; it is essentiulp however, that 
the iron be wholly in the state of sesquioxide. It is not necessarj' to separate the 
J 'r which some ol these metak yield on the addition of ammomo, unleso, 

he ver^ copious, in which case it might diagnise the colour of the liquid, 
i... ..,. jfocess IS vitiated by the presence of cobalt, nickel, m<^rcury, or silver; silver, 
howevei*, and mercury, if in the state of mercurous oiidc, may he easily separated by 
Ijydnichloric acid. According to some chemists, this pi-ocess is liable to nnc«;rtainty 
from two causes: 1st. Because the oiysulphide of copper reduces a portion of the 
protoxide to hemioxide, thereby rendering the solution colourless before the preci|iita- 
tion is complete; 2ndly. Because a portion of the sulphide of sodium is oxidised and 
converted into hyposulphite. Accordinfc to Field, however (Chemical News, i. 62), the 
process is very accurate, though somewhat tedious. 

F. Mohr^ 9 method,^ The copper-compound haring bpcn Weighed and diaaolved io 
add, is mixed, in a porc4!!lain basin, with neutral tartrate of potassium and excess of 
eaii«TiC potash, and then heated with a quantity of mi Ik-sugar or honey, sufficient to 
precipitate all the copper as cuprous oxide, the completion of the precipitation bcij)|» 
indicated by the brown colour which the liquid llien acquires. The procipitat^^d 
cuprous oride is tlien Altered, washed with not water, and gently heated, together 
w^th the filter, with a mixture of pure scsquicblorido of iron and dilute hydro* 
chloric ttciiL It is thereby dissolved in the form of protochloride of copper, the sesqni- 
ehloride of iron being at the same time reduced to protocMorido : 

Cu*0 + 2Fe'Cl* + 2HCI - 4C?nCl + 4reCl + H«0. 
In the filtered liquid, diluted to a convenient strength, und heated to about 30^ €.^ 
the quantity of iron in tho state of protochloride is determined by a graduated solution 
of permanganate of potasaiu^u (see Isox): 

K'Mn^O* + BFeCl + 8HC1 = 2KC1 -f 2Mna + 4FeKn« 4- 4H»0 ; 

and thence the equivalent quantity of copper ia readily determined. The prcsenct of 
lead, ainc, bimnuth, manganese, or iron, in the alkaline solution does not interfere wi^ 
the proceftg; silver or mercury must be separated before the precipitation of the 
cuprous oxide. (See i, 204.) 

TrrilCa mtth/jd (Compt. rend. xlvi. 230), — This is simiJnr to the preceding, excepting 
that the reduction of the cupric to cuprous oxide is effected by adding a solution of 
»tLlphito of sodium to the copper solution, previously sup frsatumted with ammonifw 
Tb* CKO««s of sulphurous acid is tJicn expoMed by boiling with hydrochloric acid, and 
the eopper estimated by means of sesiquichloride of iron and permanganate of potaa- 
■smn as abore. This method is easier of execution than the preceding, inasmuch as 
grmjmniffnr is diiEcult to waah from the cupivius oxide. 

Ci Mokf'a mtthod. — The copper is precipitated from its neutral solution by mot alii e 



60 



COPPER: ESTOIATION. 



iron (Ca*SO* + FiP •■ IWSO* + Cu"), iind the amotmt of iron in ihe toktion e«ti* 
mated by means of pcrmaxigatiate of poUastnin. 

Fteitttiann's mrihoil. — The copper is alifo precipitated by iron, but the pn>cipitate 
iii washod and diBsoWed in Beequichloride of iron (I'VH.*P + Cu ** 2FeCl + CuQ), 
and the iron ia detonnined by p^^aogatiate of potoaiium. This method giTes good 
results, C. Hoh/s proccsa ia leaa exact, and is quite injuJiniaitblfl when iron is alao 
present, as in the greater number of copper ores, 

Sirrng'a mHhod, — Tho cupric oxide in the solution is reduced t4> cuprous oxido by 
grnpO'Stigar; the precipitated oxide is dissolTed in hydrochloric acid; a solution of 
stareh and iodide of potassium are added ; and afterwards a standard fioluMcio of aci d 
chromateofpotaeaium, tilla blue colour is produced, indicating that the chromate 
is in excess : 

3Cu*0 + 2Cr*0* ^ 6Cu'0 + Cr*0«. 

The amount of copper ia calculated by the formula : 

lOO.c.g 12Cu S79 20><?. q 
' " K»0.2Cr»O». J~ 244-4 A. ' 

where € denotes the number of grains -Measure of the chromic solution HMd ; e f]w 
quantity of acid chromate of potassium in 1 grain-measuro of the solution ; ^ the 
weight of the cuprifenous substance dissolved ; and x the riKjuired percentage of copper* 
Brown' g method. — ^The copper solution is treate<l Vfilh iodide of potassium, 
whereby (mproua iodide is precipitated and iodine set free : 

2CuN0' + 2ia = Cu'I + 2KN0" + I: 

and the free iodine is removed by me*ns of a standard solution of hyposulphite^ 
of sodium, whereby iodido and tetrathiouate of socMum are produced : 
2Na»S*0* + P ^ 2NaI + Na"S*0«. 

The copper-compound, if solid, an alloy for instance, is dissolved in nitric add; car- 
bonate of sodium is added till a slight precipitate is formed, and the precipitate is re- 
dissolved in acetic acid (free nitric acid would vitiate the resnlt by decomposing the 
iodide of potjissium). A quantity of iodide of pota«eiuin is next added, eqtial to. at least 
fiix times the weight of the copper to be determined, and then the standjird solution of 
hyp^ulpbito in quantity *iuffident to remove the greater part of the free iodine^ which 
point will tie indiciitiil I - v 1 1 u' i^olour of the liquid changing from brown to yellow. Lastly 
a dear solution of ^* - ' Med, and the addition of the hyposulphite is cawtinusly 
Gontdnued till th e 1 j 1 . i h e iodiil e of stjirch is compI*"teIy destroyed.— Tlie sol utit >n 

of hyposulphite of ^ - raduated by dissolving a known weight of pure electrot\^>o 

copper in nitric acid, and proceeding as above, cacii atom of hyposulphite correspond- 
ing to 1 at. tree iodine and to J at, copper, as shown by the preceding equations. This 
method of estimating the free iodine is aimilar in principle to that of B un se n (I 265). 
If the copper-compound contains a large quantity of lead or ikju, these metids must, 
ho removed before commencing the determination, becouee tJie ycUow colour of tho 
iodide of lead and the red of the acetate of iron would interfere with the result (Chem, 
Soc* Qu. J. X* 71). The presence of iron might introduce another source of error, vus, 
that the Besqtiiorido of iron would be partially deoxidised by the hyppsulphite of 
sodium. The estimation of copper by this method in many alloys ia very rapid and 
tnietworthy* 

FititTs mtihod. — This process also depends upon the reaction of iodine on cuprous 
salts. Wlien a solution of iodine in iooide of potassium is added to the solution of a 
cuprous salt, both the free icHlineand that which is in combinution unit^ with the eopper, 
Hence^ if the solution of a cnpric salt free froiii nitric acid be reduced to the cuprous 
state, by mixing it with sulphite of sodium, the excess of sulphurous acid then cipelk*d 
by boibng with hydrochlonc acid, the solution mixed with starch when coId» and a 
Btandord solution of iodine in iodide of potasfiium added from a burette, cuprous 
iodide will be precipitated ; and where the two solutions touch, a bright blue ring will 
be formipd, which disappears at first on agitation^ but becomes permanent when the de- 
composition is rompleto. An objection to this process, however, appears to be that 
the cuprous iodide hjis a great influence on the colour of the iodide of starchy rendering 
it paler and less distinct. {0iti}ik^ Newx^ L 74.) 

^ Seheff's method, — -This method is founded on the fact that a solution of sesquichlo- 
ride of iron mixed with cuprous chloride is not coloured red by eulphocyonato of 
potassium. Hence, if a cupric solution be boiled with grape-sugar and iJkali, till all 
the copper is precipitated as cuprous oxide, and this oxide be dissolved in hvtlro- 
chloric acid, the amount of copper contained m it may be determined by adding a 



COPPER: ESTIMATION. 



91 



sUndafil solution of ferric chloride, till a drop <^ the llqiiid, placed on ii wliite plate, ia 
Teddoo«d bj sulphocyiuiato of potAfssium. 

The ttkme mothcMd ib applicable to tbo determination of the amount of cuprous oxide 
in a ioltition likewifie containing capric ojdde. (Ann. Ch. Phium. cxii. 372.) 

4. Separation of Capper /rom other MeiaU, 

From the metals of tfie second and third groups (i. 217)» and from all non-metalliis 
elementfly cxcf^it seleninm and tellurfum, copper is easily sepanitod by mdphj/dric acidj 
which throws it down aa jmlpliidB, From tho metals of the firet group (araenie^ antimony, 
&aX and from selenium and tellurium, it may for the most part be separated by the inao- 
lubility of its sulphide in the sidphidis of the Mali-nietaJ^. This m ethod can not, ho werer, 
be depended upon for the sepaFation of verysmaHqnantitiesof^Tr^rnfcand antimony from 
copper. Bloxambas ahown that it is altogether £alla<:iona when the quantity of arsenic 
present does not exceed I fjer cent, of the copper* Of tin, mncli larger quantities may bo 
overlooked, if the Bc-paration u based on tne solubility of its sulphide in sulphide of 
ammoniam. Accordinff to Freseniui^ the separation of tin from copper is more easily 
ejected by digesting the ^phide with yeUow sulphide of sodiuim ; out to render the 
separation complete, the digestion must bo repeated three or four times, 

Aniimony is more easily separated from copper than arsenic or tin hy means of 
sulphide of ammonium ; but the method does not appear to be capable of detecting 
less than 03 per cent of antimony in copper. 

According to Abel and Field (Chem* Soc. X xiv. 290) the separation of arsenic 
from copper may be much better effected by passing sulphydric acid gas, to complete 
sstoimtioQ, through the solution of the two metals mixed with excess of ammonia ; tho 
eopper is then precipitated while tho arsenic remains in solution, lu this manner ^ 
per cent, of arsenic may he detect-ed in copper. 

When tho amount of arsenic is not less than 02 per cent it may also be detected 
by digesting the sulphides Id strong sulphide of ammonium for many hours. 

For the detection Kiid estimation of extremely small quantities of arsenic And 
antimony* such as are often met with in refined copper supposed to be pure (see Table, 
ii 37), Abel and Field give the following process. 

About 200 grains of the metal are dissolved in nitric add, a small quantity of «*Vr<f/<? 
of Utid is added, equal to about XO grains of the salt^ and subsequently an excess of 
itmmonia and carbonate of ammonia, A precipitate is thereby formed which may con- 
sist of oxide, carbonate, arsenate, and antimonatc of load, and oxide of bismuth, the 
whole of the copper remaining in solution , The precipitate is separated b;^ flQtratioti, 
thoroughly wushed, and digested in a strong solution of oxalic acid,, which dissolves tho 
Arsenic and antimony. The filtrate is mii*Kl with sulphide of ammonium ; or, better, 
it is rendered alkaline by ammonia and sulphydric acid gas passed into it t^ saturation. 
Traces of sulphide of copper then generally separate; after they hare been removed, 
the filtrate is diluted to 8 o«., and slightly acidulated with hydrochloric acid. If any 
larger amount of arsemc or antimony is present, on immediate precipitate will bo 
formed ; if not, the vessel shotdd be exposed for a few hours to a temperature of 140° 
to 200® F,, when the metals, if present, wiU appear as sulphides, the precipitate being 
orange'-CQloured or yellow, according aa antimooy is present or absent. 

The precipitated snil[>hide8 are oxidised with strong nitro-muriatic acid, the clear 
Boluf ion is mixed with sal-ammoniac and excess of ammonia, and the arsenic is prncipi- 
tal«d'by sulphate of magnesium as ammonio-magnesian arsenate. The liquid filtered 
frcim this precipitate is slightly acidulated with hydrochloric acid ftnd tho antimony 
is precipitated by sulphydric acid as trisulphide, to bo ultimately determined ss 
tetroxide (1. 320). If the presence of antimony and arsenic baa been previouftly as^ 
ccrtained, the precipitation of the.9e metals as sulphides from their solution in oxalic 
acid may be cUspensed with^ and the arsenic at once precipitated as ammonio^ 
magnesian arsenate. 

A good method of separating copper from arsenic in the analysis of miners la is to 
«T»pOf]kt« the solution nearly to dryness, add hypocMoriie of Bodturn in eonsiderahle 
Cxeeii, Kbd boil for about 20 minutes. All tho arsenic then dissolves as arsenic a<!id, 
while the copper is left behind as black-oxide. (Field, Chem, Soc. J, xiv. 159.) 

From bismuth, eopper may bo completely separated by cyoftidf of potasxiumt which 
precipitates the bismuth as cyanide, ana retains the copper in solution as potassio-cupric 
cyanide. If the solution contains a large excess of adH, it should be nearly but not 
quite neutralised with potash before the cyanide is added* The filtrate is boiled with 
nydiochloric acid containing a little nitric acid, to convert the copper into chloride, 
and the eopper is then precipitated by potash. The two metals, if precipitated aa 
sulphides, may also be separated by cyanide of potassium, which dissolves the sulphido 
of copper and loaves the sulphide of bisnuitlu 



L 



68 



COPPER: ESTmATION. 



II the two metftb wtf diMohvd in nitiie «<ad, tnd no anlpbnnc add k pMaeal, the 
wpumtioii nuj be oompkidj ellbeted bj addiiig bydroehloffie add, and then a km 

rati^ of wster; vliieh thiow down this whole of th« hiamatli aa oxydikirye. If 
■ohidon k vefy add, it ahonld fint be eoncentzmtad hj erafionlioD. If iulfihitnje 
add !■ pfeaeuth the ae|inrKtiofi mnat be elfoeCed by ejanide of potaasiiim. 

Th« old method <#ae|iafati]ig copper from bumiiih bj mjeana of carbonate of am* 
iDoniar doea not giTe exact f«aalla, eome of the copper always remaining with the 
predpitaled cutonate of binniith, unloa the Bolutioo aod predpitation are repeated 
aerend timea. 

When btsnmth and cop^ exist together in an allor, thej may be aeMisted bj 
hf«»Hng the alloy atttm^y in a etream of chlonncL Chloride of bjasinth taea piiirm 
over, and may be leedvod in water^ while the oofiper remaina aa ^rotodiJoeide^ which 
may be diaaolTed in water addnlated with mtno add, and precipitated by potaah. 
(H. EoaeO 

For deteicting the amall qnantitiea of bismtith eSte^ IbQnd in commerdal eopoer and 
copper orea, the following method ia adtrantageooa. The copper bdng diBoIred in 
nitne add, a solution of nitrate of lead (abont S parte of the salt to 100 of coppor 
diaKilYed), ia added, th«n ammonia and carbonate of ammonia: the precipitate ia 
waahed with ammoniacal wata and diasoWed in acetic add ; iodide of potaaaimn ia 
added in eoosiderable exceai, and the lionid ia warmed till the precipitated iodide of 
lead ia rediaaolTcd. On coolii^, the iodide of lead will be depodted in ay^talHna 
acalei, which, if 6iee from bismuth^ are of a pure eold^yellow colour, but if bismnth ia 
present, aaaitme a dark orange or arimaon tint. This t«et is extremdy delicate, even 
0*00026 of a grain of biamn^ in 100 gms. of copper impardng a dark orange tint to 
the iodide of lead, while 000 1 gr. imparts a redmsh-brown tinge, and 0*01 gr. a bright 
erimaon. (Abel liod Field, toe. cii!) 

Fran lead, copper may be completely separated by treating the aoktion with a 
mixture of dilute gilphuric odd and alcohol, which throws down all the lead aa snlphate. 
The filtrate ia then boiled to ddire off the dcohol, and the copper predpitated by snl- 
phydric add. 

The separation may also be effected by cyanide of potaaslnn, in the manner abore 
deacribed for Msmuth. 

The aeparatioD of these two metals by carbonate of ammonia is nerer quite complete, 
atill leaa oy caustic potash. 

For determinizig the small qoantitied of had and hitmuth found in commercial 
copper, Abel and Field gire the fbUowing method, founded on that aboTe described for 
the estimation of arsenic and antimooy. 

The nitric add solution of about 200 gms. of the copper is mixed with a sm^ 

Suantity of solution of phosphate of aodium ; ammnnJa is then added in exoeaa^ and 
tie predptate is norified Irom copper by wasiting with animoniacal water. This pre- 



dpitate is then dissolred in hydrochloric add; the solation, rendered alkaHne by 
amtnmiia is treated With ezceafl of sulphrdric acid ; the prf>cjpitated solphidea of lead 
and bismuth are thoroughly washed, ana £saolTed in dilate nitnc add ; and the solution, 



nearly neutraHaed with ammonia, ia dieted with a small <|uantity of hydrated oxide 
or baJsic nitrate of copper, which pred^itatea the oxide of bismuth, while lead remains 
in solution. The washed precipitate is disaolred in nitric add, and the bismuth is 
a^ianted from the copper Xij ammonia ; the oxide of bismuth thus obtained ia purified 
b^ washing, and its weight deteimiued in the usual way. The solution containing the 
mtrat«s of lead and copper ia mixed with carbonate of sodium and excess of acetic 
add, and the lead ia predpitated as chromate by add chromate of potassium. [It 
might also be predpitated by sulphuric add and alcohol] If the copper contains iron, 
that metal will be predpitated together with the bismuth. In thia caae^ the predpi- 
tate must be redisaolred in an add, and the biamuth predpitated aa sulphide by 
vulphydric acid 

From cadmium.— The best metho<i of separating copper and cadmitim ia to mix 
the solution with ctfonide of potatxiutth, till the precipit^ite first formed redisaolvcd, and 
pasa sulpbydHc acid gas through the liquid. Sulphide of cadmium ia then prt^dpit-atedj 
while the copper remains dissolred aa sulphide. The filtrate is then boiled with hydro- 
chloric and a little nitric add, till all the hydrocyanic acid ia expelled and the copper 
is precipitated by potash. 

Copper may also be separated from cadmittm by carbonate of ammonia^ in which 
carbonate of cadmium ia insoluble; also by lulphocyanate of potasdum, whidi predpi- 
tatea the copper (ii 68), bat not the cadmium. 

From silver, copper is separated by precipitating the silver ae chloride. 

For the separatioii of copper from mercury, gold, platinum, and the allied 
metals^ aee those metak. 



COPPER: ESTIMATION. 



68 



6. ValKation of Cdpper Ores, 

I. B^ the dry ivay. — Tlie ordmaiy method of assaying copper ores, consists of a 
««riefl of processes, jiimilar in principle to the operations of smettbig on the largo 
ecaje. OxiiiiHcd orea mid ftmiflce-procliictfl, if moderately rich» are melted witJi black 
flax (a mixture of nitre and burnt tartax)^ where bj a button of metallic copper is 
obtained, which* if necessorf, may be subseqiiciitly retined. PoortT oiidised orea and 
Blags are firet melt«d with iron pyritc^ to obtain a regnlus containing euproua anl- 
I phidi*t which is then treated as b^^low. 

[ Solphnretted oiue and fiiniacc-products^ if ricb, aro first roasted in a muffle, to con- 

J tcrt the sulphidea into oxidea. Poorer ores, like those of Cornwall, containing from 

r '6 to 10 per cent of copper, are first fused with a mixture of nitre and borax, wTiereby 

I B portion of the anlphnr is removed ; the siliceoiia and earthy matters are separated in 

the form of a Titreons slag, and a button of regnlus is obtained, containing the whole 

, cf the copper as sulphide, which may th<>n be roasted. The roasted ore — or regulas — 

is next melted in a crucible, with black flax and a mixture of borax and gloss ; the 

more oxidable melali then pass into tlie slag, and the copper is reduced to a button 

of coartt^ eopper, which may b^ refined cither by fusing it with borax in a current of 

I ftir. CT by cxpeUing it with lead. 

[ This proGe/m doea not yield very exact results^ the percentage of copper which it 
[sbowi being ahrays less than that obtained by the wet method of assaying. For 
^detaUlk iee I/W** Dictionary o/Arts, Mmiu/acturcs and Mims, i. 839 ; Percy* s Metal- 
^ iurgy, L 464. 

HaiiniTs method, —TiuB method, which is exact, but somewhat difficult of ezecn- 
i lion, serres to determine the quantitiefl of copper, lead, bismuth^ cobalt, and 
1 91 > eke 1, wiiitting in ores, slags^ alloya^ &c;: it involves the following seriefl of opera- 
l^ons. 

A Booiting. — 100 cents* of the ore, containing sulphides or pnlphatee, is roasted 
tcm * lOfurting test (j^g, H2)« £,rst per ^r, then with carbonate of ammonia, tUi all tho 
I palphur is expelled* Ores containing gypsum, heavy spar, or al- 
I kaUne sulphides^ and in which the metals are united with sulphur Fig. 142. 
kor arsenic^ aro prepared for ro£i5ting by ftwing 100 cents of the _^ff 

[ore with 100 cents of vitrified borax or glass, and 10 cents of 

eolopbonyf nnder a layer of 300 cents comtnon salt, in a covered 
, cmeible heated for 4 to | hour, in a muffle or air-famace; a regn- 
' ]ua is thereby obtained containing the metals. If the metals are 

in the form of oxides, associated with gypsum or heavr spar, 
L from 10 to 30 cents of metallic arsemo must be added to the precedmg mixture. The 
k tnlphide of sodium, which is produced hj the action of the sulphur on the borax, and 
sates into the regulus, is washed out with hot water. 

b, Omversion ^ the fHttala into Arsenides. — The roasted ore or regnlus is tritu* 
[ ntsd with 100 cents of metallie arsenic, and heated for 8 or 10 minutes in a covered 

laj erucible {Jig. 143), placed in a closed red-hot muffle, as long 
oomboartible anenic vapours are evolved. Some of the metals are 
> thereby converted into arsenides, viz. Cu*As, Pb*As, Co* As, Ni'As, 
and Fe*S ; part of the iron is converted into ferro«o- ferric oxide; imde- 
composed snlpliate of lead into sulphide ; antimonious oxide into ar- 
senide of aotimony ; oxide of bismuth into arseniferous metallic bis- 
muth, while the oxide of zinc remains unaltereiL 

Snbstauces not originally containing sulphur, such as black copper, 

nickd-ailver, alues containing cobalt and nickel, &c., are treated in 

' the floelj dividedi state (flle^ laminated, or pulverised), in quantities 

of 60 to 100 cents, with 100 cents of metallic arsenic as above. The 

product is either a sintered button or a fused mass. 

c. Union of the resulting imtallic arscnidfS into a whole, and Mfpa' 

ration 0/ the Lead and Bumuth by fiman unth appropriate fiu^t, — If thecnaciblo 

used in the preceding operations is free from cracks, and gives a clear ringing sound 

I vim fltnick, the wmbb oontained in it is covered with lU to 20 cents of iron wire (ac- 

I eoid^ to tho amomat of lead preeentX ti mixture of 200 cents of black fiux, and 

60 to lOOeents of vitrified borax (the quantity being greater as the amount of earthy 

matter in the assay is leas), and the whole is covered with 300 cents of purified common 

I mah« and a Itirap of charcoal. If the crucilile hJis been injured in the preceding <)peni- 

tioni^ a new one must be taken. The crucible, with its cover on, is heated in the 

• Tl>«cg«# tier* spoken of. li not the weight io-caliwi by ilie Cfimlih Mtayer*, (5= 4 irr»<,n»>. but tlM 
^h\ch In G^TiBBH uMfing la eallwl :i pound, \(M)*>t which ranln* 11 Pro&ir-centntf, eiiimt to J-^Siramnwa 
(vr 6TM fralai) tt Freiberg, u>d JtM graniinet In ibc Otjcrhari. 





64 



COPPER: ESTIMATION. 



mafflt^- furnace for 25^ — 30 minutes, or in the air-f^maco rathpr longer, to n temperaturo 
KraJuiilly ruisecl to the melting point of eopp«ir. A successful op<?ratioii yields a well* 
nised alag of dark green to black colour, covered with a grey crust of common salt, and 
8t the bottom a regulus,^ on which ^ if the subgtiince under examinatioD coutaina lead^ 
that met^ii is found to have opparat^ either on the bottom or at the aide. In tho 
former case, the lead is removed with the knife ; in the latter^ the regulna, with Uj6 lead 
eide uppermost, ia broken up in a mortjir, the mall<L?ablo lead then e^parating from the 
brittle arsenic compound, which is mixetl with a few cent* of colophony, and i^s8«rvt?d 
for fhrther treatment. The lead contains nearly all the silyer in the ort?^ together with 
the bismuth and a little antimony^ but no copper. If lead is iboent, the bismath sepa* 
rates in like manner on the anrfaee of the regulna ; butt being brittle, ia not so easily 
separated firom the arsenides. In thi9 C4iae, it is necessary to add from 10 to 20 cents of 
granukted lead, as well as 15—25 cents of iron ; the excess then gire« approxi- 
mately the quantity of bismuth. It must, however, bo remembered that about 4 per 
cenL of lead is lost in the process. 

d. Separation of ihf Artenide of Iron and of the Zmcfrom iht Anmidcg of ColaU, 
Nickd^ and Cc^p]^ 5y ojtidisina fusion on a Scori/ier. — The arsenides arc placed, 
together witn &0 to 75 cents of borax, on a sconfier {f^, 144), 
Fi^. 144. aurroaiided with glowing coals at nearly a white heat, and fused 

at a strong heat with the muffle closed After a minute or two 
the muffle is partially opH?n<^d,, and as soon as the assay has 
acquired a bright vaporising surface, it is brought a little nearer 
to the orificG of tbe moffle, and the temperature is so regulated 
that Bmsll films of oxide may form upon the surface^ and pass into the boroDc If the 
temperature is faised too high, the assay becomes bright, and if it be kept too low, 
the entire surface becomes oxidised. The process ia complete when the sur&ce be> 
comes tranquil, and f^uaea of arsenic begin to escape. At that stage, the whole of 
the iron and dnc aw separated, the latter by scorification and volatilisation. If 
the assay beoomes covcfeo with a cmst before the temperature falls, thero is a de* 
fieieney of boraac, and the fjfooess must be repeated on a new scorifier with fresh borax. 
The button thus obtaiuod is left to cool partially, then completely quenched in water, 
and carefully cleaned from slag by tapping it with a hammer. If the assay has been 
removed firom the muffle at the proper time, the skg will be quite free from cobalt^ 
nickel, and copper. 

t* Removal of the ejcceu cf Arsenic by t^Mlisation, — The metallic button still eon* 
tains excess of arsenic, which ia cxpelk^d by mixing it, according to its si^e, with i to 1 
cent of bontx-glass ; iayinpr it, wrappt*d up in thin paper, on a lump of charcoal having a 
cavity about half an inch deep, or on a aconfiermade of powdered coke and pitch ; melt- 
ing it in a closed muffle; and, when the metal exhibits a shining surface^ and begins to 
give off afsenic vapours, exposing it, with the muffle open, to a moderate heat tUlitno 
longer gives off vapours of arsenioua acid with rapidity, and such vapotirs are no 
longer perceptible on taking the scorifier out of the muMe. The but ton, which tlien so- 
lidifies ^i-ith a dull black sw^Mse, is weighed; it contains the dejinite compounds, 
Co*As, NiMs, and Cu'Aa. 

The borax-glass dissolvefl the basic arsenit^ of cobalt, which is apt to form on the 
sur&oe of the melted assay if the temperature is not kept high enough, and might 
binder the Tolattlisation m the excess of arsenic This salt is again mlitced to the 
metallic state 6jt soon as it comes in contact with the carbonaceous support 

/, Separation of the Anenidts of Cobalt from the Arsenides of Nickel and Copper , 
and determination of the amount of Cobalts — The weighed button of regulus wrapped 
op in paper, is laid upon a scorifier contiiining from 10 to 30 cents of borax, snr- 
rounded with hot coals and heated ncarlv to whiteness ; the muffle is closed ; and the 
assay quickly brought to coruscation. The scorifier is then brought nearer to the op^en- 
ing of the muffle ; a few pieces of charcoal are laid in front of it; and the arsenide of 
cobalt, which is the most oxidable of the three arsenides present, is U-fl to be scorified 
by the borax,^at a temperature at which the fused assay exhibits a clmn but not b[w- 
cular surfece,— till the surface becomes covered with a green film of arsonite of nickLd. 
If the substance under examination does not contain cobalt, this appearance is oh* 
served in the preceding operation, t. The loss of weight which the regulua has sus- 
tained, consiata of Co^As, containing 61 per cent, of cobalt. 

g. Separation of the Arsenide of yickei from the Arsenide of Copper, To scorify 

the arsenide of nickel, the button of regulus still containing Ni^As and Cu'As, is 
treated with borax in the manner above dwjcribed, till the melted metal becomes 
bright, no more green films forming on its surface^ and it begins to give off arsenic va- 
pottrs from the decomposition of the animide of copper. The chief point to be iit- 
tended to in this opcrution ia the duo regulation of the temperature, which must he 
lower in proportion tM the assay contains a larger profjortion of the eoaily ^^ible ar- 



COPPER: FLUORIDES. 



65 



jLtdt* of eoppw- The low of weight consists of Ni^As, and a portion of urs^mie ToTa- 
^Hiftcd from the aroenide of ooppur ; the nickpl caunot^^ thereft>re, be cakuliited directly 
froui this loss, bat most be estiniHt^^d after the amount of copper has bepn determined. 
The aepamtion of the arsenide of nickel from the uftMJiiide of cropper may be effected 
with rofflci«nt accuracy, even if the profxtrtion of eopp«r is belowr 1 per cent. 

A. VolaiUusaiion of the Arsenic cofubined with the dapper, mid d^Urmination of the 
proportions 0/ Nickel and Copper, — The button of regnlua, wrapped up in paper, 
IS laid upon a glowing charcoal scorificr ; the inufllo m c?lo&ed for a while ; and as soon as 
the butJ^on is fused, the scorifii^ is brought near to the mouth of the muffie, which is 
heaped up with red-hot ooala to the height of about 1 J inch ; and the asnaj is kept at 
a temperature about equal to Umt roquirvd for the cupellation of silver, till films of 
basi£ cuprous arsenit* begin to show themselves here and therw on the clean surface 
of the metaL It is then exposed to a higher temperature, till it ejthibita the bluish 
green colour of pure copper, and the films which form upon it, make thtnr (iftpPArance 
no longer on the sides, but at the top. The asaay is then taken out of the fire and 
cooled* The button of coppep, whatever its colour and texture^ must be malJeable, and 
h«To a small quantity of cuprous oxide on its uurface. 

The weight o( the copper button giyes directly the proportion of copper in the 
a!u«ay. To determine the nickel, the copper in calculated as Cu*As; tJie reeiulting 
Weight is deducted from the known weight of the arsenides of nickel and copper tx>ge- 
ther, and the dififerenee givea the weight of the Ni^As, which contains 61 per cent of 
nickcL 

The process of assaying just described may be greatly shortened if one or more of 
the tnetali above considered are absent. If« for exunple, the cDpnferous substance is 
fr^ *--— -i>kel and cobalt, as is the case with moat copper ores and many pTt>ducts ob- 
i per smeltingt the operations/ and y become unnecessaiTT and the process 

it :. '• the Beparation of arsenide of iron, including more or less antimony and 

EKDc («) ^m the aisenide of copper, and the separation of the arsenic from the copper 
bj Tolatilisiition. (Plattner, Beitrag sur Erufeiterung dtr Probirhinstt Freiberg, 
1849; KerfM BuUmkundf, u. 140.) 

n. Assa^ff of Copper Oret in the wet way. — The ore being dissolved in nitric acid, 
the determination of the copper may be made by either of the metliods given on paces 
67 — €0, Of the methods by toeickt amUt^fis, however, the one that is generauy, 
indeed almost exclusively, employed, is the precipitation of the copper by iron, as it 
has the advantage of not reqainng any mcial treatment for separating the copper 
from the iron in the ore. More exact results would be obtained by the use of pure 
xinc as the precipitant (p> 57)% 

Of the ttoiumetric methods^ that of Parkes is the one most generally used for the 
valuation of cooper orea, as it likewise is not interfered with by the presence of iron, 
which nearly all theea ores contain. Brown^s process is exuct and expeditious, but it 
requirea the removal of iron and lead. It is, however, tiniitfectod by the presence of 
arsenic, antimony, tin, or «inc, and is therefore very useful for the aumlysis of tilloys. 

An expeditious method of obtaining an approximut© eatimiite of the quantity of 
copper in an ore or slag, is to dissolve a given qunntity of it in nitric acid, mix the 
solution with excess of ammonia, and compare the colour with those of a series of 
standard solutionSi prepared in a eimilar manner. (Jacquelin.) 

6. Atomic Weiffht of Copper. 

The atomic weight of copper haa been determined b^ reducing a weighed quantity 
of the protoxide with hydrogen, and weighing the residual metjd. In this manner, 
Berseiius, in 1820 (Pogg. Ann. riii. 182), obtained, as a mean of two experiments^ 
the number 31'fifi. Erdmann and March and (J. pr« Chem. xxi. 3Sd) found, as a 
of five closely agreeing experiments, made with cupric oxide obtained from the 
mitrale, the number 31'73, which may be received as very nciir the truth. Dumus 
Qi. Phy»» [3} Iv. 129) by the same method, and from the weight of cuprous 

[phide pfodnoed from a given quantity of copper, obtained numbers var) iug between 

'5 and 321, whence bo regards 31 75 as the true atomic weight. 

OOPPSS, SniKmAJill* Syn. with BiopT^SB. 

C0F»S3ft, TlMtromiOmm or. Protofiuoride of Copper, or Cupric Fino^ 
riffr, im formetl by ilinsolving cupric oxide or its carbonate in excess of nqiieous hy- 
<in>fl«i'^'' ' •" - 1 ' rTietallic copper is not sensibly dissolved by the acid), and evaporating 
Ihr rv solution. As the excess of acid goes o£^ small, light blue crystals sepa^ 

lato tp >nd. If the quantity of cupric carbonate ia suMctent to neutralise the 

CTe«t4T yuH of the acid, the coinponnd sep^irates out during the digestion j with a still 
larBI^T quj-ntity of earVwmate, the oxyfluoride Cu*iX* + H'0 is formed (Berzelius). 
The cryvtala, which an* but sparingly soluble in cold water, are decomposed by hot 

Vat. n. ^ 



I m trat< 
^^ CO; 



k 



wS 



COPPER, GREY— COPPER: IODIDES. 



water, yielding an acid solntion and the insolnblo oxyflnoridp. The crystala lieate<l 
■with sulphuric acid yield 116 per cent, of ctipric sulphate, and when ignited with 
ex(^H9 of lead-oxide give off 263 per cent, of water (B©rBeliu«). Protofinorido of 
eopper Mmbines with the fluorides of the alkali-metals, fbroiing black compounds. 

The Hemijluoridi;, or Cuprous F/ttori^r, Cu'F, isobtaLned by treating cuprous 
oxide with aqn&ouji hydrofluoric acid, washing the product with alcohol, then presiding 
And drying. It is a red powder, which melta when heated, appejiring black while in 
the liquid state^ but peooTering its red colour on cooUng. In the dry »tat« it is per- 
manent in the air ; but when mois^t it is converted, first into a yellow mixture of cnpric 
fluoride and hydratcd cuprous oxide : 

4Cu-P 4- - 4Cur + Cu*0 ; 

and afterwards into greon cnpnc oxjfuoride : 

4CnF + 2Cu*0 -I- 0* = 4(CtiF.Cu*0). 

It is insoluble both in wat^r and in excesa of hydpofluoric acid^ but soluble in strong 
hydrochloric acid* In the latter it forms a bla^^k sohiHon, from which it it precipi- 
taled by water in the form of a powder, which ia white at first but afterwanJs becomes 
Tose-coloared. (Bcrzolins, Pogg* Ann. i. 2L) 
Borofittoride of Copper^ CuBF* (iee i 634)t 

COP PES, ORST^. (iS^ TETIlAH£IlRTni). 

COPP£Jtf HTDRXSB OF. CwTI. Wben a aolutiou of cupric sulphate is heated 
with hypopho'iphoroufl arid t<5 about 70'^ C, hydride of copper ii dcpoHite<l aa a yellow 
precipitate, whicli aoon ttirna red-brown. It giree off bydrogen when heated; takes 
flro in chlorine gaa ; and when treated with hydrochloric acid, is converted into cuproua 
chloride, with ©volution of a double quantity of hydrogen, the acid giving up iti) hy- 
drogen as well as the copper-compound '. 

Cum + HCl = Cu«Cl + HH. 

Thii action is remarkiiblef inivsmucli as metuUic copper is hut very slowly acted upon by 
hydrochloric acid. It afTords, indeed, a striking instance of the poiarity of atoms 
alluded to in the iirticlea Chkmicai. Affinttt (i 857), and Contact Action (ii. 12). 

COPP&S, IwntOO. See Cofpxb, Svlfhidbs of (p. 74). 

COPPER, 30DZSES OF. Cuprio lodtde^ CuF, ia not known in the fre<e 
state. An amtnonitf-cvpru- iodidf^ '2(CuI.2NH*)HrH^D, ia produced when cuprous 
ioflide, moiistencd with ammonia, is cxpoaed for some time to the air, a blue solution 
being then formed^ which, when mixed with alcohol, yields small, diirk-hlue tetra* 
hedrons of the ammonio-iodide (Rammelaberg, Fogg. Ann» xlviiL 162). Ac- 
eording to H. Hah n, it forms crystals belonging to the tri metric system^ with the faces 
OS Poo ,»P.E'ao.|P».JI*c».P. Kiitio of axes = 3362 : 1 : 1*462 (Jahres- 
ber, d. Chem. 1859, p. 217). According to Bertheraot, the same compound is 
obt&inod by mixing a concentrated ammoniacal solution of ammonio-cupric chloride, 
or sulphate, with iodide of potassium. It is soluble, without decomposition, in am* 
monla and in a email quantltj of water^ hat a largo quantity of water^ especially if 
hot, decomposer it, with separation of a green oxy iodide. Alcohol and ether do not 
act upon it in the cold, but decompose it when heat^ed. Thia compound exposed to 
the air gives off ammonia, and leaves green oxyiodide. When heated, it first gives off 
iodide of ammonium^ then detonates and leaTOS a brown-rod residue containing cuprous 
iodide. 

Cuprous Iodide, Cu*I, is produced: 1. By heating finely divided copper with 
iodine. 2. By precipitflrtiiig a solution of cuprous chloride in hydrochloric acid with 
iodide of jrotuAitiumt or by adding iodide of potassium to the sohitiou of a cuprio 
salt mixed with sulphite or hypoBulphit<? of sodium. 3. By precipitating a dissolved 
cupric salt with iodide of potasaium, half of the iodine being set free : 

Cu'SO* + 2KI ^ K^SO* + Cu*I + I 

The j>recipitate mast bo washed with alcohoi to free it from adhering iodine. 4* By 
precipitating the aqucoua aolutiou of 1 at. cupric suJphat© and at least 1 at. ferrous 
sulphate, with iodide of pot-assium (Soubeirsn, J. Pharm. xii. 427); 

2Cti'S0* + 2Fe%S0* -f- 2KI ^ K'SO* + (Fe*)^'(SO^)" -j- 2Cn«L 

Cuprous iodide, obtained by precipitation, is a brownish- white p*jwder. When 
heated, it gives off 4 |jer cent, of water, —agreeing with the formula 2Cu'l.II-0,^and 
fit a red heat fuses mto a brown mms^ which yields a green powder. It is but 




w 



COPPER: NITKIDE— COPPER ORES. 



67 



imperfectly deeompoaed l^y igmfcion in a ntpe&m of hydro^ ffos (H. Bos^, Pogg. 
Ann. IV. 110)* When ignited -mth peroiid/f of mangatiese^ it is resclved into iodine 
TBpour and cupric o3dde (Soulu iran). With nitric acid^ it jielda vapour of iodine^ 
nitric oxid« gas, and cupric nitrate ; and with strong Bidphttric ucidf it jields iodine 
Tapcyur, tidpliurotis add gas, and cupric Bulphate : 

Cii«r + 2H^0« - Cii»SO* +1 + S0» + 2H«0. 

Cnproua iodide boiled with water^ and rinCj iin^ or iVo«, yields mi^tallic copper and u 
di«soIvcd iodide of the othftr metal (Bert he mot, J. Pharm. xiv, 614), Aomj^hs 
/x«</ aikidi* form metallic iodidea and separate cuprous oxide ; a similar rvaetion is 
produeed yj carbonaU of potastium or todium^ carbonic acid being liki*wtso erolred* 
Gnpfoot iodidd Is not decomposed hj baiyta, strontiiij lime, or alumina. (Ber<^ 
themot). 

Ammimio-euprtm* iodide. Cm^2NlI*. When dry ammonia-gas is passed over 
enpffOiiiB iodide^ the oompoiind absorbs ammonin, becoming hot, and acquiring a 
brown colour; but on appljing a gentle heat, the whole of the ammonia is onvon off 
(Eammelsberg). When plates of copper are enclosed m a bottle together with a 
cupric salt strongly supersaturated with ammonia, the liqoid being frequently shukon 
till it loses its colour^ and then poured into a bottle coatuinin^ aqueous iodide of po- 
taseiumi which must be afterwards dosed, ammonio-cuprous iodide separates, partly 
in cokmrless shlniD^ prisms, putly as a white crjHtaUiae powder. It cannot be dried 
without decomposition, as it gires ofTaiamonia when exposed to the air. The colonr- 
l(«s liquid from which the compound has separated, turns blue in the air &om forma* 
tioD of ammonio-ciipric iodide. (Levol, J. Pharm. [3] iv. 328.) 

COF^XX, irXT&i3IS OY. Cu*N. This compound ia formed, together with 
wat*T, when dry ammonia-ga« is passed over very loosely coherent cupric oxide heated 
to 250*^ C. The product, which generally coataina more or less undecomposiKl oxide^ 
and sometimes a Utile mtrate^ 'm a dark green, ftometiiiies nearly black powder, which 
at 300° C. is resolved into its constituents, with alight explosion. The temperature 
mt whidli tiiis deoompodtiou takes place yaries, however, with the nature of the sur^ 
rcntikdiikg gas ; in oxygen gas it takes place at comparatively low temperatures ; in air it 
rcqmres a higher tempertituro, and in ammonia gas still higher. Sulphuric acid decom- 
poses it with violence, giving oW nitrogen und leaTing metallic copper ; other acids act 
in A similar manner, those whichf like niiric acid, oxidije the copper, acting BtiU more 
rioleotly. In dry k^drocMoric add gaa it yields sal-smmoniac and cupric chloride. 
Ckhrifu produces cupric chlorido, with evolution of nitrogen. Aqufous ammonia does 
not appear to eliminate f;as from the compound, but hecomes blue by contact with it. 
(Sch rotter, Ann. Ch. Pharm. xxxvii. 13L) 

When dry ammoniacal gas is passed over red-hot copper, the copper becomes crystal- 
line and brittle, but does not appear to take np any gas (Qm. v. 444)u From Dick's 
experiments^ it appears that copper is not rendered brittle by heating in ammonia-gas, 
unless it contain Hi cuprous oxide, in which case tbe brittleness appears to bo due to 
the poiroaihr resulting frjni the reduction of the oxide by the hydrogen of the ammonia, 
( A«y» Mitallurf/i/, i. 278,) 

When a ball of copper connected with the positive pole of a six-pair Grove's battery 
is made to dip into one end of a long glass trough containing solution of saKammoniac, 
andm platinum plate connected with the negatiTe pole into the other end^ the sal- 
ammoniac being kept in excess, the liquid becomes blue, and a nitride of copper collects 
at the negative pole, in the form of a chocolate-coloured aggregation, which, after washing 
and dijmgt has a density of £9. Ten grains of this suhstonce give oif 0*214 cnbic 
i&diet of nitrogen gas when heated, ieaving metallic copper. (Qrove, Phil Mag. [3] 
xix.100.) 

COFFSB, aitas or. (See page 19.) The following synonymes requiro 
i notice : 



Black Copper ore 
Blue Copper ore 
Einerala Copper ore . 
Grey Copper ore 
Of^wn Cr>pper ore , 
Indiffo Copper ore 
CM^edral Copper ore 
Variegftted Copper ore 
Velvet Copper ore 

Y«Jlow Copper ore 



Native black oxide. 

Azurite or blae carbonate (I 783). 

Dioptaa*', Cu^HiO* + 5aq. (See Silicatm.) 

Tetmhedrito (q. v,) 

Malachite or green carbonate (i. 783), 

Native prot^»s^dphide {ii. 74). 

Niitive red oxide (ii. 7t>). 

Purple copper (iL 80)^ 

Native sulphate of copper and aluminium. (See 

IiSTTsoMira and Sulpbatka ) 
Copper pyrites (ii. 79). 
f2 



1 



68 



COPPER: OXIDES. 



COPFSR, 0XI31S8 or, a. Protoatidecet Cupric oxide^ Cti^or OuO. Black 
oxide of copper; Dentoxi^dt dt ciih*re ; Kvp/eroxj/d, — This oxide is found initiv<^ as 
Mdaeomte OT Blavk Ctypper {K%ipfer»chw'drze). Itoccura abnndaatly at Kewi^naw Point, 
Luke Snperior, ixi calies (perbapa paeudomoipha of red copper ore), with truiicat-ed 
angles; more cenerally massive. Specific gravity^ 625 (Whitnej^ 6952 (Ram- 
melsberg). Hardaesa = 3. Colour, dark sti^el ffrey in the crystals, black or greykh- 
blaok Trhen maseive. 

Cupric oxide is prepared : 1. By contuued iguition of copper in contact with the 
air, 2. By exposing cupric sulplmte to an intense red heat^ or the carbonate op 
nitrate to a moderate red heat. A conTement mode of preparii)^ it for use in organic 
anBlynis ib Id ignite eopper amithy-Bcales, moistened with a sufficient quantity of nitric 
acidto conrert the whole of the metal and red oxide into black oxide. As tbuu ob- 
tained, it is le*s hygroscopic than when prepared by i^iting the nitrate. The heat must 
not be zaLied too high, or tiie ojdde will fuse, and will then hti difficult to pulverise. — 
3, According to Picinus, cupric oxide may be easily prepared by exposing a mixture 
of 1 pt. copper filings and 2 pts, deliquej+ced cupric nitrate \q the air, till the whole li 
converted into a basic salt, and then igniting this Bait.-— 4. When caustic potash in 
added by drops to a boiling solution of a cupric salt till the acid is saturated, the whole 
of the copper la precipitated as anhydrous black oxide, which may be freed from potash 
by washing with bailing water. 

Cupric oxide prepared as above has the form of brown-bkck brittle scales and 
granules, or of a brownish- black powder, which, when titrongly heated, asiiumes for a 
while a pure black tint. At a AiU red beat, it melts and sohdihes U> a mass having 
a cr3rst:altiue fracture. By heaticg It to commencing redness in a silver crucible with 
fpfmi 4 to 6 times its weight of hydrate of potassium, washing the fused ma^fcs with 
water, andseparating the fioccnlent cupric oxide from the cryst^line portiou by leviga- 
tion, it may be obtained, in regular tetraHedroua having a strong lustre. (B ecqaerel, 
Ann. Cb, Phys, IL 122.) 

JenKSch (Pogg, Ann. evil. 647) fotmd crystals of cupric oxide imbedded in cavities 
in the hearth of a citfcining farnace at Freiberg ; they wei^ iron-black, shining^ of 
■pecific gravity (jIoI* nearly as hard as fluor-spar, and belonged to the trimetric 
system, exhibiting the faces oo P » P co . P oo . |P. Inclination of faces : ooP : coP* 
99° 39*; oDp : f » - 113<> 58'; ocP : P (» =- 122*^ 58'. They were all twin-crystals, 
thefkce of combination being a P. 

Cupric oxide is reduced to the metidlic state hj gentle ignition with hydrogen or 
charcoal; by hydrogen even at the temperature of boiling linseed oil. (Schrotter.) 

It is likewise reduced to the metallic state by potajfsiufn and sodtum, at temperatures 
somewhat below the melting points of thoBe metals, and with vivid incandescence. With 
fused c//a nid4; ofpoiamiu wi it y iel ds eoppi' r and cy a n ate of potassium ( L i e b i g). Wh en 
gently ignited with nffiaUic copper^ it is converted into cuprous oxide. With phos- 
phorus at a red heat^ it yields phosphide and phosphate of copper. Mixed with pho^- 
Vthoric oxide, it detonates slightly on the approach of a red-hot coal, and is converted 
into cupric phosphate and brightly glowing fnw'd globules of phosphide of copper 
(Leverrier). A mixture of cupric oxide with excess o£ sulphur is resolved at a red 
heat into cuprous sulphide, euiphurous anhydride, and a trace of cupric sulphate i 

2Cu*0 + S* ^ Cu^S + SO'. 

If, on the pontraj^', the cupric oxide is in eicess» cuprous oxide and cupric sulphut« 
are produced,, and only a trace of sulphurous anhjdridet excepting when the heat is 
raised to the point at which the cnpric sulphate is deoomposed (Max Jordan, J. pr. 
ChtaxL xxTiiL 222): 

7Cu«0 + S = Cu'SO* + 3Cu*0. 

When protoxide of copper is boiled with a solution of stannotts chimndf, stannic oxide 
is precipitated, and euprons chloride dissolved (Proust; A. Vogel, Kastn. Arch, 
xxiii. 86). Hydral^d ffrroua and cupric oxides are converted by mutual decomposi- 
tion into by d rated ferric and cuprous oxides ; the latter of which may be dissolved out 
by ammonia (Levol, Ann. Ch. Phys. Ix, 320; also J. pr. Chem. xiv. 115): 

2Fe*0 + 2CtL'0 ^ Fe*0" + Cu*0. 

In presence of potash or soda^ and with the aid of beat, cupric oxide is decomposed by 
arsniioua anhj/drtdr^ the products b* iiig cuprous oxiile and arsenate of potassium. The 
decomf^osition is effected by mixing 150 pts. (2 at.) of cupric oxide with 100 pts. (rather 
more than J at,) of ar^enious anhydride, and with excess of soda, and digesting the 
mixture at a gentle heat, with frequent agitation, till all the protoxide of copper is 
L'onTcrted into hcmioxide: the sohition contains arsenate of sodium : 

4Cn-0 + A3"0» + 3Na'0 ^ 2Cu'0 + SNa'AsO*. 



J 



COPPER: OXIDES. 



SO 



TVhcn AtninoTiIa U iia«d in place of aoda, onl)- half of the protoxide of coppi-r is eon- 
Ttfted into hptmojdder the rest remaios dbsoked in the ammonia, fornjitjg a blue 
solution, and no doeolomtion takes place till pota^ih or soda is added* A mijtture of 
Af«enioaf» aeid with carbonate of potasBiuin or sodium or quick'timc does cot convert 
the protoxide o! copper into tlie hemioxide (Bonnet, Pogg, Ann. xxxvii. 300), When 
proto^uipkidg of tinon i« fimetl with protoxide of copper, sulphide of copper 13 formed 
(Karsten). Protoxide of copper la reduced to the state of bemioxide hy boiling it 
with vanons organic fiabstancefl, f, ff. with mt of turpentine, 

Hpdrattd Cupric Oxide, or Ou^rie Hffdratf^ CuHO, or CuO.HO, is formed by 
preciniUtipg a diMolred cutiric salt m the o&ld, with a slight exeess of diiut^^ caustic 
pota«h, quickly waahipg the blue precipitate with cold water, and drying it at the ordinary 
l«mpenitiire of the air. The hydrate generjjly turrw black frfjm aclmixture of auljy- 
droDB copricoxide, even during the washing and drying. According to Palmatwit, it 
ia more duiable when obtained by the mHion of caiiBtic potajsh on <^rbonat« of copper 
pfttTUMifily w«E WQohed with wat-er. After dr)'iug, it forms greenish-blue friahk lumpn^ 
having a conchoidal fracture ; itM taste ia strongly met^iUic. In the diy stat^ it r^jmaiua 
nndecompooed, e^ren at 100^ C, but at a somewhat higher temperature it is convert^jd 
into anhydroua black oxide ; thus, if the hydrat«i be heated on pper, the chang* takea 
pWe at a temperature not high enough to char the pfiper. It is couTcrted into the 
KLadL oxide, with considerable diminution of volume, when kept for some time under 
water ; alik^, by boiling in siiliition of eauirdc potash. Alcohol d-iea not decompose 
the hjdnite. either in the fresh or in tha dry state (Proust, Ann. Cb. Phya. xxxii. 41)* 
Mnefa of the Blue verdiUr or Bremen preen which occurs in commerce, consists of 
hydistad cupric oxide, prepared by precipitating a aolation of sulphate of copper with 
cai^BStic poCoflb oif 16° B., washing the precipitate, again treating it with caustic potash 
of 16^ — 18** B., and lastly washing it thoroughly. The potash-solution mast contain 
a little carbonic acid, in the state, in short, in whifh it is obtained by slaking 50 pts. 
of lime in an aqueous solution of 80 pis, of pearlash ; otherwise the colour will be 
qwiled. (Gent el e.) 

According to Fr 6ray (Ann. Ch, Phyw^ [3] xxiii. 161), hydra ted cupric oxide, obtained 
by precipitating a solation of cupric sulphiite in the cold with a lai^e excess of potash, 
and then drying in vacuo, con tarns Cu'll*D', or Cu03H0. 

Cttprie Oxygert'Salts. — Cupric oxide has a strong affini^ for acids, diBSoIring in 
tli«m eaail^, imd with evolution of heat, even after ignition; the hydrate and carbcinuto 
dinolre with still greater facility. The last-mentioned compounda likewise dissolve 
in ammoniacal salts, and lil>erate the ammonia on boiling. The anhydrous cupric salts 
az« mostly white ; the hjdruted salts have a blue or green colour. They are for the 
moat part soluble in water^, and the soltitiona hare a metallie taate and redden litmus. 
At a i»d heat they give off their acid, provided the acid is volatile ; the sulphate, 
bowern; requirea a strong beat to decompose it. For their behariuur with reagents and 
befbn the loowpipo, see page 55. 

AmmoniO'Cnprie O it trf**.— Cupric oxide appears \o unite witJi ammouia in more 
than one proportion. A dark azure-blue liquid is formed by exposing an ainmoaiacal so- 
lution of cuprous oxide to the air; or by bringing copper filings in contact with aqueoua 
ammonia and a sufficient quantity of air, — or cupric oxide, either anhpfdrous or hydruted, 
with aqueous ammonia ; or by allowing aqueous ammonia mixed with a few drops of 
Ml^ammooiac solution to trickle through copper-turning«t. If all acifls, even carbonic 
acid, be excluded, the ammonia, according to Beraelius, appears to dissolre scarcely a 
trace of the anhydrous oxide ; but on adiung a drop of the solution of an ammoniacal 
•alt, the oxide is abundantly dij^>Ived (compare Wi t ts tei a, Repert. Ivii 32). The pro- 
duct is a dark anire-blue liquid. PkoBphorus decolor! ses it, by forming a compound 
of cuprous oxide and ammonia, and ultimately precipitates the copper in the metallic 
^plate ; xinc and cobalt likeMrifte precipitate the copper. Iron reduces the copper im- 
"frdly ; arsenic, tin, and ca<lmtum reduce it sparingly, and lead exhibits but mere 
oes cif reduction (F ischer, Pogg. Ann. viiL 492). According to Wetz lar (Scbw. J. 
I 101), iron exerts no action on the pure solution, but slowly precipitates metallic copper 
L the solution mixed with s^-ammoniac, eommon'salt, nitre, or sulphate of potas- 
I, sodulci composed of copper and ferrous hydrate forming on its surface at isolated 
Dtir and extending till the liquid is decolorised. A lai^o excess of ammonia prevents 
• pfrecipttation, especially if the solution be mixed with nitrate or sulphate of potaasium 
dphMrouMOcidw^dsiA to the solution of cupric oxide in ammonia, throws down nearly 
I llie Ripper in the form of wid- brown cuprous oxide, containing small portions of i*ul- 
burous acid [and ammonia?] (A. Vogel). The liquid, when tlilutod with a large 
' of water deposits the cupric oxide in the form of hydrate. Potash— of which 
* quantity is required in proportion as the ammonia is in greater excess — 
I precipitatca the cupric ozideir at leaat after a while, in the fonn of hydrate 



70 COPPER: OXIDES. 

leootaining poUsbP], the predpitation, aiToonUn^ to BenceliiUf being complete; on 
bofUng the bqttld, black oxide of copper i* immediately precipitated. 

When amtiirttiii^^ not in excess, is added to eapric udta, the precipitate luinallj coo* 
aifltf of a basie salt free from ammonia; Kane, boverer (Aon. Ch. PHjb. [2] IxxiL 
283), on one occaidoQ, bj precipitating a aolntion of cnpric chloride vith ammoiiia, 
obtained a blue precipitate reaemblung bjdrated cnpric oxide, wluch waa eaay to 
wBnh, and did not ioie ammonia doriog the waahing. Thi» precipitate undemrent no 
change at 149® C. ; but at a eomewhat higher temperature, it waa diooompo^d with a 
slight hiBBing notae, yielding nitrogen gaa, ammonia, a huge qttantity of water, and a red 
miztnre of copper and cuprous oxide. It wob found to be free from cUonne, and to 
consist of 4Km3Ca*0 + 6H^0. 

Malaguti ami Sarseau (Ann. Ch. Phya. |3] ix. 431) obtained the eomponnd 
4yH*.CiL*0 ^ 4H'0, in fine blue cr}'stals br paasmg ammonia-gas to complete eatura^ 
tion through water in which bade cupric chromate was suapended, etyrtaUiaing out a 
portion of the copric chromate, and leaTing the mother^liquor under a bell-jar together 
%iith a mixture of alaked lime, sal-ammoniac, and lumps d quick'-liroe, so that it might 
eraporate in an atmosphere of ammonia. Bine aystala of basic cvuprie ehnymate then 
formed, together with green crjstala of ammonio-cuproua <mde. These oyatala deli- 
quesce and give ofiT ammonia when exposed to the air, and when heated, decompoee 
with incandescence, leaving metallic copper. When a number of them lying together 
are heated, so that one begins to glow, the incandescence extends to the others, and 
Tcrmicular tubes of copper are formed, corerod hflfe and there with oxide. 

The solution of cupnc oxide in ammonia, also the anunoniacal solution of baaic enprie 
sulphate or hyposulphate, dissolres celluloae (cotton, linen, hemp-fibre, paper, &c\ 
this solrent power increasing with the amount of copper in the solution, and the oellu- 
lose ia precipitated in the amorphou^i stjite by aeids^ salt, sugar, &c (Schweizer, 
J. pr. Cfaem. IxxiL 109; Ixxri. 344 ; Peligot Compt rend. xlTii. 1034.) According 
to Erdmann (J. pr. Chem. Isxri 38o), the celluloee is not actually held in solution, 
but merely swollen and held in suspension, like a Larch in water (i. 820). 

Hricioxidbof CoppBB,orCrrpROU9 Oxide* Cu*0 — Ccu*0. or Ctt'O, also called 
Dioxide^ Stthoxide^ and Bed oxide of copptr {Proioxidt d€ cuivre^ Kupferoxyduti, — This 
ojdde is found native in two forms; 1, Red copper, {EoikkupfcrtTzX whick occurs 
erystallised in the regular system, generally in octahedrons and with octahedral 
dearage: also massire, granuhir, sometimes earthy* Specific graTity = 6'85 — 6*15, 
Maidiieia*3'/» — 4. Colour red, of rarious shades, with adamantine, sabmetalHc, or 
earthy lustre; subtraniparent or subtranslucent; occasionally crimson-red, by transmitt^ 
Ughtv. Streak brownish red, shining. Fracture conchoTdal, uneTen. Brittle, It occurs 
in the Bannat, in Thuringia, in Tuscany, in the Isle of Elba in cubes; in Cornwall, 
at Cheasy, neat^ Lyons, where crrBtals sometimes an inch in diameter are found em- 
bedded in lithomacge ; at Ekatherinenburg in Siberia ; abundantly in South Australia ; 
io the Lake Superior region, and several other localities in North America. When 
found tnlaree quantitios, it forms a valuable ore of copper (Dana, ii 101). ^2. As 
Copper-bloom, Chalotrichite, or Capillary red oxide of copper (^M/>/*<?r- 
UutM\ which crystiillises in the trimetric system, forming prisms with the acute and 
obtuse edges truncated ; ob^rvt^l piMnea, od P . oe f oo . qd I* ao. It is usually found in 
flue capillaiy ciystallisations, grouped or reticulated. Cleavage rhomboTdoX fierfect 
Specific erarttyBiS'B. Colour cochineal and crimson-red. Occurs st Rheinbreiten- 
bach, Ifoldawa, and Nischna TugEsk. (Dana, ii. 122.) 

Prfparait&JU — L By igniting 4 pts. of copper iilings with 5 pts, of the protoxide, otr 
29 pts, copper filings with 24 pts, anhydrous cupric sulphate. — 2. By heating 100 pta. of 
CrystaUised cupric sulphate with 67 pts, of crystallised carbonate of sodium, tall the water 
of erystallisation is entirely expeUed, and heating tlie residue Io bright rodnesa with 
25 pts. copper filings,— 3, A mixture of 5 pts. cuprous chloride (obtained by evaporat- 
ing a solution of cupric chloride and fusing the residue) and 3 pts, anhydrous car- 
bonate of sodium is fused at a gentle he^it. Mid the cooled mass is lixiviated with water 
to dissolve out the sodium-salts : cuprous oxide then remains as an amorphous powder, 
of a fine red colour (Wo hi er andLiebi^, Pogg. Ann. ixi. 581).— 4. A solution of 
equal puts of cupric sulphate and sugar, is muied with a sufficient quantity of soda- 
ley to dissolve all the copocr, and gently heated ; cuprous oxide then aeimrutes in the 
form of acijBtftlline jxjwder (Mi tscherlich, J. pr. Chem. xix. 430).— 5. A very fine- 
coUrared oxide is obtained by pouring a cold saturated solution of cupric sulphate into 
an excess of potash-ley ; leaving the precipitated cupric hydnie to settle; then, after 
washing and pressing, diffiiaing it, whDe still moist, through 7 times its weight of 
water in which 3 parts of sugar are dissolved ; adding a solution of 2 pts. hydrate of 
potaasium in a quantity of water equal to that which has been used for dissolving the 
SQgar; agitatiag the mixture strongly; straining it through linen; and heating it 
over the water-bath, with brisk agitation. Cuprous oxide is then deposited, and, after 




COPPER: OXYBROMIDE, 



71 






I wrll wasbedt exhiVats a fine red colour. — 6. Cwprntts oxide nmy bo obtuinf^ in 
sliining cubical oysf^s, by filling h t^t-t ubc iinth a in;utr*il s^Dlution of cupric 
litrate, placing a mnall (quantity of cupric oxid« at the bottom, introducing a dean 
efrip of copper-plate, closing the tube air-tight, and leaving it to it*K?lf fur alevrmontht 
(Becqucrel). The ozida is sometimes fonnd in a similar form on the surface ot 
antique bronzes which have heen horied in the t^arUi for a long lime. 

In whatever way cuprous oxide may bt» prepared, it^ colour in liticr and more tip- 
proachiiig to crimson, in propt^rtion as it is purer and more finely divided. The 
eijatala, irhfther natural or artificial, yield a crimM>Q powder by tritunition. 

Caproos oxide is reduced to the tnetaUic stat^ by gentle ignition with ckarcMti or 
k^drogffi ; ako by poiOMium at a tempeniture a little above the melting point of the 
latter. It imparta a ruby-red colour to glasa-jliu:^^, if fused in euch a manner aa to 
avoid oxidation. It diasolvea in exceaa of kttdrochioric acid, forming a solution of 
capfuua chloride, which is deoompoaed by wat«r. Moat other Hclda, viz, ^vlphuric, 
jtitmph&rie, acetify dxalic^ tartaric^ and citric acid, decompose it, forming eupric suits 
and separating metallic copper; niiric acid converts it into cupric uitmte. Hence 
there are but few cuprous oxygon-salU ; indeed the only such snlta known are the sal- 
pKil^. aod the double sulphites of cuprosura and the alkali -metak, pn^ducixl by tifatiiig 
cupric sol utioDS with alkaline sulphites (ii. 56), With bromine-waitTj it yields cupric 
bfomide and cupric oxide. 

Hydrated Cuprous oxidt, or Cuprous hydrate, 4Cu*0.H"0? — "When a solu* 
ru of cuproua chloride in hydrochloric acid ia poured into exceaa of soda or potaBh*ley, 
,_ when recently precipitatetl cupric hydrate is boiled for a few minutes with a solution 
of milk-aagar containing a tmrndl quantity of carbonate of sodium, the liquid then di* 
luted with water, and the precipitate wtie^hed, cuprous h^nlrute is obtained as an orange* 
jeUow powder, which oxidises to cupric hydrate, on exposure to the air. It retains 
Its water at 100*^ C^ but gives it up completely at 360°, without change of colour ; it 
does Dot, indeed, assume the red colour of the anhydromt oxide, prepared by the 
methods prmoualy described, till it ia heated to commencing whiteness. 

Amman io-cuprous oxide. — When cuproug oxide or hydrate, or a mixture of cupric 
*'b and coppcr-filingfl, ii placed, together with excess of ammonia, in a stoppered 
le^ a colourless liquid ia obtained, which oxidises so quickly on exposure to the 
gr, that it exhibits a blue colour while being poured in a thin stream fi:x>m ooe reasal 
another (Bergman n, Opmcidix^ iii. 3S9 ; Proust). 

SasqutoxtDE or Copprk. Cupric add, Cu*0'? — Not known in the separate 
te. Some of its salts have been obtained in the utute of solution, by passing chlorLue 
into potash or soda-ley in which hydrated cupric oxide is difiused ; but they cannot 
aVtjdned in the solid state, inasmuch as they are decomposed, with violent evolution 
Hpf o«VLT..n soon after their formation. Cu prate of calcium has however been obtained 
i u of a beautifbl roae-coloured substance, by mixing chloride of lime with a 

a [ cupric nitrate; it decomposed but slowly (Kriiger, Pogg, Ann. Ixxii. 44o)w 

_ to Crum (Ann. Ch. Pharm. Iv. 2 IS), the oxygen-compound of copper con- 
in this salt is a sesquioxide, Cu*0*. 
FamoxXBS of Coppbr. — 1. Formed by agitating the hydrated protoxide i^-ith a 
OBsa of very dilute peroxide of hydrogen at a temperature of 0°C. — % By 
, cupric nitrate with excess of aqueous peroxide of hyflrogen, and pr*^cipi- 
the copper at 0^ C. by caustic potash added in moderate exceta. The rvaulting 
da of copper is washed with cold water, pressed between bibulous paper, una 
in Tacuo. YcUowish-brown powder (or olive-green, if eont^uninated with hy- 
^ conric oxide), fasteltts, and without action on vegetable colours. Contains 
ly twioo as much oxygen as the protoxide. At a temperflture short of 100*^ 0., it 
off oxygen, and is converted into protoxide; in the moist state, it decompoaee in 
— 1 of 12 houTBi even at ordinary temperatures the decomposition being greatly 
,_„d by the preaence of strong caustic potash. It is insoluble in water. With 
it forms oimnaiy cupric aalts and peroxide of hydrogen (ThAnard), It is 
pi not a higher oxide of copper, as Th^nard supposes, but rather a compound of 
! oxide with peroxide of hydrogen. 

O OyMM, OSCTBKOHSXXIII OF. A solution of cupric bromide, treated with 
f ^ ft«"«fK^ft^'*ti not aufficient Ibr complete precipitation, yields a hydnitiKl 
klilbiinAQf ftptle greeo powder, which gives off its water when gently 
\w3t imijIUi tnftper&ture give« o£r bromine, and leaves a grey compound 
f of aapric oxide with cuprous bromide. (Lowig.) ^ 

I Bromine- wat#r forms, with cupric oxide, an inwluble olive-green aubetance* whicn 
lii probably n mixturo of cupric hypobromit-e and oxybromido. It liberates nitrogen 
* I ainmonia, does not discharge vegetable colours, is decomposed by the weaieat 



72 



COPPER : OXYCIILORIDKS — PHOSPHATES. 



tfcldot with pToIution of bmtnin?, und at 100* C. gives off oxygen, bromine, and water, 
and ii **oiivi rttnl into ciipric oxv bromide. (Balard^ J, pr, Chem. iv- 179.) 

OOFPSS&f OXTGS^QRXl>SiB QtW* Four of tlip^o componndii (cnpric oxjchlo- 
ndcfl) are known both in the anhydroua aad hydrated utatea. 

ti. Cu'ClO, or CaCI.Cn^. Ad' aoueoua aolution of cuprie chloride, treattd with a 
quantity of p>ta.sh not auificicnt to a«H>Bipoae the whole of it, yields a pale p*en ppe- 
cipifalo, cooKistini:^ of Cu'CI0.2H'0^ which girps off i\s wat«r when Btrongly heated, 
leaving the auhydroufl compound in the form of a black powder. Thin, when moistf^ned 
with watfcr» i.s converted into a bright grern powder, containing 2Cu*Cl0*3H'O j and 
tills Wt hidrali?, hpat^d to 133^ C, givea off | of itfl water, leaving a chocolatD-eolooi^d 
powder, conmting of Cu*C10.H^. (Kane, Ann. Ch. Phys. bcxii. 277.) 

b, Cu"Cl*0' = *JCuCL3Cu*0. The a3ihydrou« compound, which is obtained by gently 
heating the hydnite, forms a brown powdp-r; at a r&d heat, it gives off oxygen, and is 
converted into a compound of cupric oxide and cuprouB chloride : 2CnCI.3Ca'0 = 
2(Cu«CLCu'0) + 0. (Prouat.) 

This oxychloride oecurs in nature^ associated with vnrious quantities of water, ba 
AtacamiU (i. 4211), Hydrates are also prepared by the following processes : 1. The 
anhydrouji compound is converted into the hydrate hy contact with water, 2, Moist 
cuprous chloride exposed to the air, m converted into a grer n mixture? of hydrated 
protochloride, wliich may be extracted by wattT^ and hydrated cnpric oxy chloride: 

6Cii»Cl + 0' ^ 4CBa 4- 2CuCL3Ctt«0. 

3. By digesting aqueous protocliloride of copper with the hydrated protoxide ; or 
by mixing it witli fl small quantity of alkali, sulHeient, howerer, for the precipitation 
of the dissolved suit. 4. ^y expo!»ing copptr-fuil to the air, moistening it repeatedly 
with hydrochloric acid or solution of sabammoniac, and exhausting the product with 
water. Tlie arlitcially prepared salt is a pale green powder. It is pppparcd, by the 
last process, on the lai^e scale, and constitutes the pigment called Bmnsirkk flretn^ 
which has the advantage of not being affected by sunlight. When gently heated, it 
gives off water, and is converted into the black annydrous compound Cold sulphtirie 
acid turns it brctwn^ and separates protochloride of copper. When heated^ it gires off 
hydrochlorie acid. It is insoluble in water, but easily soluble in adds. (Gm, v. 441.) 
A Cu*C10- = CuC1.2Cu*0. Thia comjiound remains on a gre^u hydrate when the 
ammoRio-ehloride, Nll'CnCl, ia treated with water. When lieatcd, it gives off ita 
water, and becomes chwolate -brown, and if alt-erwards exposed to the air, regains a 
portion of the wnUr which it has lo!<t. 

COPPEJL, 0XrmMUOmX3iWi op- Cu*F*O.H*0, or 2CuF.Cu*0 + H*0.— Palo 
green insoluble powder, formed by digesting aqueous hydrofluoric acid with excess of 
cupric carbonate, or by deeomposing cupric fluoride (ii 66), with boiling water. (Ber- 
sseliuH.) 

COFFER, OXTasir-SA^TS OF. For the general properties of theae salt^ 
spe ji. 55, M; for the particular descriptions, see the aereral Acids. 

COFFSR OJC-rSirx;.FHn»S9. The compound Cti^'S*0, or 6Cu=S.Cu*0, is ob- 
tained, accorcting to Pelouz<% by dropping snlphide of sodium into anammoniacal fiobi- 
tion of a cupric salt, heated to 75^—80^ C. tdl fho blue colour just disappetirs. then 
quickly collecting and washing the reHultiiig precipitate. If the temperature ia allowed 
to rise during the precipitation to 95°— ^100^ C, an oxysulphide of different composi- 
tion is obtained, which, if boiled witli a cupric salt containing excess of ammonia, de- 
colorises and reduces it to a cnproua salt. 

An oxysulphide is Likewise formed when lulphide of eopper is heated in a solution 
of a cupric salt, most readily if the solution is alkaUne. 

The brown nubstaaee which forms in tht> first instance, when copper is heated with 
oil of vitriol, for the preparation of sulphun^m* acid, has the composition 2Cn*8.Cu^O, 
By the further action of the acid, which abstracts copper, this compound is converted 
into 2Cu^S.Cu''0 ; and when the evolution of gas is at an end, the residual black sub- 
stance has the compoitition Cu'S.Cu^O. (Maum^n6, Anm Ch, Phys. 131 imii 311 ; 
Handw. d. Chem, iv. 735.) 

COFFmx, FHOSFHA^SS OF. Three cupric phosphate* occur as natural 
minertdSj vl^. : 

Cu'PO^.CuHO. 
Cu"PO*.3CuHO. 
Cu*P0*,2CuP0« + 5H»0. 

(See these Minerals ; also Pkosfuatks.) 



Libethenite 


. 4eu''O.P'a» + H'O or 


Phosphocaleite 


. 6Cu^O.PH3* + 3K«0 or 


Thrombolito , 


. 5Cu«0.3PO*+ 10H*O or 



COPPER: PHOSPHIDES— SILICLDE. 



78 



COPPESi FHOSFKXIlSa OF, Cbpper and phMphoms unire readily nt high 
feiiip«?niturfs. By curefiilly Lliyipping phosphorus on melted cDppor in a crueibk, the 
metal in;iy he made to taka up as much as 11 p(*r cent, of phofephorue. Phosphorus in- 
CTQAsm the fusibility and hardness of copper, and when present in liirge quantity, 
reDden it brittle at ordinary temperatoies. Copper cont^uninp: 11 per cent, of phoa- 
t>hon» is extremely hard, and can Bc&roely he touched by a file. It has h more or 
less Bteel*grey colour, and is 8usc4*ptihle of a fine poIi«ht but speedily taruiahM| eape- 
cittlly in a London atinoHphere* {Pcre/s Metallur^, L 279.) 

Several definite pho8phidee of copper have been prepared by H. Eoaq (Pogg, Ann. 
ir. 110; xiv. 188 ; xxir. 321, 331). 

a, Dicupric Fhosphid*^ Cu^. — Greyish black crystalline ^abetanee, obtained by 
paasiD^ hydrogen gaa over dicupric phosphate (Cu'HPO*), at a very strong red heat* 

A mixture of dicupric phovphide with chJorute of potjissinm and cuprous sulphide 
(tr levigated coke, to increase its conducting power, is used a.«» a fuse for firing chargea 
of gunpowder by mftgneto-electridty* (Abet, Chem, Soc. J. xiv. 183.) 

h. Trieuprie Phosphide^ Oq'P, is obtained by paH»in^ phosphoretted hydrogen 
gas, (a) over heated protochloride of copwn 3CuC1 + HT = Cu"P + 3HC1, or (#) 
through a solution of cupric iOilphftt4' (H. Rose» Pogg, Ann. xiv. 188; xxiv. 321). 
The first process yielda it in the form of a black powder, which, when strongly 
igmted in a close vessel, is converted into a groyish-bkck metalljc-looking mass, but 
&m not aaaume the red colour of copper at any temperature. By the second proceaa, 
it is obtained in black flocks, which, after pjentle heating in vacuo, assume a red colour, 
like that of copper precipitated liy aine (H. Rose). It docs not fuse at the melting 
point of glass, but is more fusible than copper, (Land grebe, Schw* J. 411, 464.) 

Trieuprie phosphide a exhibits a phosphorus -fiamc on charcoal before the blow- 
pipe, /i does not ; a gives off half its pnosphoros when very strongly united in a 
cunvnt of hydroj^n gas (H. B ose, Pogg. Ann, iv, 110). Both varieties dissolve readilv 
in nitric acid, with formation of phosphoric acid, especially «, if not previously heated. 
Hot strong sulphuric add dissolves J9, with evolntion of sulphurous anhydride. If not 
previously heated, ^ diasolves in liytlroehloric acid more readily thiin purt'eopper, with 
evolution of non-Bpontaneously iiiflamraabl*j phosphoretted hy<irogcn {Buff)» ^, if not 
pPBviottsly heated, is permanent in dry air, but when exposed to a moLst almosphere 
Hi converted into cupric phosphate. Before the blow- pipe, it burn!* to a !dack b**ad of 
ct^ric phoq)hat«, wnich solidifies to a white enamel on couliiig. (Land grebe.) 

€^ Tricuprous Phosphidf*, Cu'P, or Ccu'P. — Produced by passing phospho- 
retted hydi^en over cuprous chloride or sulphide : 

3Cu*Cl + H«P = Ca«P + 3HC1; 

also by pAAsing hydrogen gas over trieuprie phosphide, at a very strong red heat It 
is a black powder, or, after strong ignition, a light grey mms, having the metallic 
lustre. On charcoal, before the blow-pipe, it emits a phosphorus-flame. It is insoluble 
in hydrochloric acid, but dissolves in mtric acid or aqua regia, forming cupric phos- 
phate. {H. Bose.) 

COFFER, FiTitFIiS. (See Sui^fkidbs of CoFrmi and Iron, ii. 80.) 

COFFISR, KES. (See Coft'KU, Oxides of, ii. 70*) 

COFFISl, SEZiKirZBSS OF. Cuprie Seienide, Cu'Se, is obtained by pfe- 
cipit-sting cuprie sulphate with aelenhydrie acid, in black flakes, which become dark 
grvf when dry, and acquire metallic lustre by pressure. It gives off half its selenium 
on distillation. (Berseilius.) 

Cup rou9 Stltnide, Ca*Se, or Ccu'Se. Found native, as Btrrdiamtt, at Skrikenmi 
in Svaden, and near I^hrbach in the Hart«, in sofl thin dendritic crusta, with silver- 
whita colour and metallic lustre. The same compound is produced by heating copper 
with selenium, aud by igniting cupric selenide in a dos© vesstd. Before the blowpupo 
it etmts the o<iour of seleniuTO, and fuses to a grey bead of brittle, easily fusible copper, 
stiU retaining selenium. (B e r e e 1 i u s.) 

SeUnide of Copp tr and Ltud. (See LhAlD, SELBKinii ok) 

4l0IP9SBp SZ&ZCATBS OF. The mctamlkatt, Cu'SiO', occurs native with I at. 
^ iniflL it Jiqpi^r ^'^^ ^^^ ^ ^^' '^^^^^i lUi Chr^Bocolla. Other copper silicates of 
' 'bii'^yilatd eorapotition are likewise found. (See Sii>icatrs.) 

C0W9'WM% SHiICII^B of. Silicon may Ijc melted with copper mto a dnctile 
bead before the blow- pipe, and the compound leaves a fiiliceous skeleton when dis^- 
solveti in adds (B e rz eliu s). By heating copper to intense whiteneas with whit^* sand 
and chaieod, a compound is obtained perfectly soluble in acids, the solution when 
evaporated leaving 6 per cent of ailica (BerBcHus). Percy, by tbi« process, obtamcd 



74 



COPPER: SULPHATE— SULPHJDEa 



& crmtpoimd oontaming 1*82 p^r oent, silicoD. It had ft ip«ctl&e grarity of 8'70t ▼>* 
midlesable wbile eold^ bnt brittle at a rt*d henL 

A roinpoiind containing from 10 to 11 j^t cent, of wlicon is obtained by heating 
eopper foil Or filingm with f ilicofluoride of potaaeium or sodium, and metalUc soditun 
(Deyille). It varies in colour from veUow to gr«^riah white, i# Tety hard and brittJe, 
Cttsily pnlTeriaed, more fusible than copper, and is readily attadced by nitrie acid, either 
strong or dilnte, with f^oratian of a grey powder: the aolotion gelatiniaea on erapo- 
nfcion. (Percy's Mtttdlurgy, I 283,) 

COFFSXt SirXPSA.TB or. Kenti^ cnpric Bulphate. Ctt'SO* + SB?0 ooeura 
natiTe as Cyanoaite iq. t\)\ a basic inlphate, Cn'SO'.eCuHO, also occurs natire aa 
Brockantite (i. 664 ). A solphato-cbloride of copper, called CotmMU^ ia foimd in Corn- 
wall (ii U). See also SciJ^HATBS. 

C099ER, SITZiPBXBES OF. Copper has a great affinity for sulphtir, bornitig 
in ita Tapour, and tixiiting w ith it eren at ordinaiy temper^itareti, when the two sub- 
stances are tritumt^ed together in the finely divided stat^". There are two weU de- 
ftned solphidea of copper, Cu'S and Cu*S, corresponding to the oxides, and four mors 
of less defined constitutioD, but snppoded to contain respectirely 2, 3, 4, and 5 at, 
sulphur to 2 at copper. 

PnoTostJLFHtDB OF CoppBB, or CupBic SuLPHiDB, Cn*S or CuS^ This 
eompoond is found native, as ComUin,, Indiffo copper, Biiu copper , or Breithauptite^ 
sometimes in hexugoniil pliLtas, with very {perfect ba&al eleava^ more commouly 
massive or spheroidal, ciyatiUJine on the surface. It ia soft, fiexibJe in thin leiivea, 
of specific grafity 3*&, opaque, of bluish-block colour, with faint reainons lustre. It 
occurs^ with other copper ores, at Leoeang in Saltzburg, Keilee in Poland, Xdinger- 
bauscn in Saxony, Manaield in Thuringia, and in the fomaroles of Vesuvius, where it 
forms a sooty deposit or block networic, like a spiders web* (Gm. v. 422; Dana^ 
iL 65.) 

Cupric sulphide is thrown down from cupric salts by snlphjdric acid or Fulpbide of 
ammonium, as a brown precipiUte, which becomes brown-black when collected, mncL 
greenish-black on drying - it oxidises very quickly on exposure to the air, iicquiring an 
add reaction, and, if moist, is completely converted into cupric sulphate (iL 57)- It is 
likewise produced by triturating cuprous sulphide with cold strong nitric at^id, which 
abfltiaetB half (be copper. 

When cupric sulphide is treated with hot nitric add, the copper is oxidised, part 
of the sulphur is converted into gnlphuric acid, and the rest is separated, so that the 
resulting solution contains both nitrate and tftdphate of cfipper. Hot coQcentrated k^ 
droehloric acid slowly convertJS it into cupric chloride, with evolution of sulpbydrie 
acid, and separation ot sulphur ; this reaction takes place most easily with the recently 
precipitated sulphide. Cupric sulphide decomposes siiver-MlU, the copper dissolving 
and sulphide of silver being prectpitateil It is insoluble in aqueous sulphurous ad^ 
potash, and the fixed alkiiline Hulphidea, slightly soluble in sulphide of ammonium, 

HaitistJLPHinB OF Copper, or Cvpaous StfLpHtna, Cu*S— ecu's, or Ot^S, 
also caUed DUulphide of ro^/>rT*— Found native, as Copper-^nnce^ ViittoMS atpper^ or 
Bcdruikiie, in cmtols of the Xnm^Xnt system, with the form of six-sided prisms, oo P . 

00 Poe . oP* Kadoof brarhjdiiigonal, macrodiagoaal and principal axis, = 0*5822 : 

1 : 0-9741. » P; a P = 6(P 25'. Cleavage veiy imperfect^ panOlel to oq P (Kopp), 
Twin eiy&tiils are of frequent occurrence. It also occurs masdre, with granular op 
compact and impalpable structure. Specific gravity = 5*6 — 5*8. Hardness = 2-o — ^3. 
Colour blackish lead^grey; lustre metallic; streak lead-^erey, sometimea shininflp 
Fracture conchoidsl. Sectile. Fine crj- stalls of this minenuare found in the Cormsh 
minf« ; it occurs also in Haddingtonshire, Ayrahire, and Fair IsUnd, Scotland- The 
compact and massive varieties occur in Siberia, Hesse, Saxony, the Banna t ; also in 
Connecticut^ New Jersey, and other parts of the United States; large and brilliant 
crystals are found at Bristol, Connecticut. Co^rer pvrites, purple copper, and bhu^ 
copper, occur as pseudomorpbs after copper^Iance, (Dana, ii- 46,) 

Cnprons sulphide is prepared: 1. By triturating copper ^th sulphur. When 64 
pis. (2 at.) of finely divided copper, obtained by reducing the carbonate with hydrogen^ 
and 16 pta, (J at.) of milk of sulphur are dried together over oil of vitriol, and tritu* 
rated together in a mortar, so gently that no heat is produced bv the friction, they 
combine as soon as a uniform mixtiu^ is attained, and Jbrm I'luish cuprous sulphide^ 
the combinatioii being attended with a development of heat which raises the mass to 
redness. If the proportion of the copper to the sulphur he even slightly altered, the 
experiment fnils, even though the mortar be warmed. If the mortar be wanned to 
20^ to 26° C, it is not necessary to dry the powders previously, and monjovor, fiowers of 
sulphur may be used instead of milk of sulphur, only that longer trituration is 



COPPER J SULPHIDES. 75 

taiy to indace combination (WinkelblocK Ann. CIi, Phami- xxi. 34). Sulpliido of 
copper is idao formed bj triturating copper fi.lings with sujplmr and water. — 2. Thin 
COpptr leaf burns with ririd inflammation in a ghaa flask m which eulphiir htm bet'ti 
heat«dtiU it TolutiliBes, 8 pts, of copper filinga mixed with 3 pt«. of pjimdcd sul' 
phur unit*?, with incaodeBcence^ rrhf^n heatt-d. Tbo gtune comMund i& obtained by 
ftiaing together pUt«e of copper and pomided Bulphnr, urrunged m a crucible in alter- 
nate layers.— 3. By igniting protoxide of copper with »u]phur. — 4. 100 pts. of dry 
cupric sulphate heated to wbitoneaa in a cmcible lined with cbarcoaJ, yield 47'6 pts, 
of cuprous nulphidej mixed with a few granules of the metal (Berthier, Aun Ch. 
Phys. xxiL 236.) 

Artificial cuprous ffolpliide baa a density of 6 9775 (Kara ten); it is of a bladdsh 
lead'grej colour^ and fuses much more easily than the metal 

Cuprous sulphide is not decomposed when heated to redness out of contact of air; 
but if the air has access to it, comfaustioa takes place, and sulphurous anhydride and 
free cupnc oxide are produced. When heated to rednesa in a current of aqucovs vapour^ 
it is but slightly decortipo»ed ; but at a white heat, it yields Lirge quantitit's* of hydrogen 
gas and eulphiiretted bydrogen, togetlier with Bublinied;&tilphur, and llie copper is <xim- 
plctely reduced to* the met^c state (lieguQult, Ann. Ch. Phya, Lxii. 378). [There 
la no statement as to what becomes of the oxygen of the water.] By phosphoreited 
h^fdro^tn gas at a red heat, it is very slowly resolved into Cu'P and suJpliuretted hy- 
drogen (£ Boae) : 

3Cu*S + 2PH* - 2Cti«!F + 3ffa 

It is not altered by ignitioD in a stream of hydrogen (H. Rose). It is net decom- 
posed by chlorine gas at ordinar}" temperatures^ very slowly when heated (H. Bose, 
Fogg. Aim. xUi. 640). It dissolves with diMculty in strong boiling ki/drochloric acid, 
wi^evolntion of sulphuretted hydrogen and fannadon of hydrochloric acid and cuprooA 
oxidfl ; in heated nitric acid^ it dissolves with »i*pamtion of sulphur^ wherea,** cold 
nitric acid withdraws half the copper and leaves protosulphido of copper. 100 pts. of 
ettprcms sulphide, ignited with 77 pts. or rather less of nitrt^ yield from GG to 70 pta, 
of metallic copper (Berthier). %VTieij cuprtms sulphide is insed with a mixture of 
eau§tk wda and carbonate of sodium^ part of the copper is reduced. The same reducing 
action is exerted by a mixtoio of carbonate of sodium and charcoal, whereas carbonate of 
sodium or potash alone has no effect. When 100 pts. of cuprous sulphide are ^ised with 
70 pts. of dry carbonate at sodium and with charcoal^ one half of the copper ia reduced^ 
and the rest combines as sulphide of copper wilh the sulphide of sodium which is 
Ibnned. When 1 pt. of cuprous sulphide is heated to whiteness with 4 pta, of carbonato 
of aodiimit in a crucible lined with charcoal, nearly aU the copper is rrduced- 100 pts, 
of eitprous sulphide ignited with 400 pta. of diy carbonate of sodium and 30 or 40 pta, 
of ifVO, yield at most GO pts. of copper. AIho, when cuprous sulphide is heated to 
whiteness with baryta or lime and charcoal, part of the copper is reduced, and sulphide 
of copper and barium or calcium formed at the same time (Berthier, Ann, Ch. Phys. 
xxxiii, 160). When cuprous (sulphide is fused withpro^art'i? of lead, the mass boils up 
and yields sulphurous anhy^lride, cuprous oxide, which combines with the undecomposed 
leadn^xide^ forming a red shining slug, and metalhi? leiid ; 100 pts, of cuprous sulphide 
aodSOO UthargSf yield 104 pts. of copper contjiininglead. With from 300 to 500 [its* of 
lHhaise, a gfy» semidiictile alloy, rich in lead^ is obtained. When 1000 pts. of 
lithai^i!' aro nsed, 2 90 pts. of ductile lead separate out, and 2500 pts, of litharge yield 
385 pts, of lead. It is only th*^refore with this last proportion that the whole of the 
sulphide of copper is resolved into sulphurous anhydride and cuprous o-:dde ; 

Ctt^S + 3Pb»0 - Ctt*0 + SO* + Fb» 

Aeooidingly, 160 pts. {I at) Cu*S shonld separate 624 pts. (6 at) of lead - lOOi WO 
(Berthier^ Ann, Ch. Phyi* Ixxxix, 246). Metallic lead exerts no deeomposiug action 
OB en^foos sulphide when fused with it (Kiiriten), Cuprous sulphide, ipnited 
with wpricoxidt is easily converted into sulphurous anhydride and metallic copper, or 
atprotts oxide. I at. Cu"*S and 2 at. Cu-0 are completely converted bto sulphurous 
annydride and copper : 

Ca«S + 2Cu^0 T^ Cu ■ + SO'. 

WiUi 6 at Cu*0, the only products ore sulphurous anhydride and cttprons oxide: 

Cu^a + 6Cu*0 ^ 4Cu*0 + SO^ 

Any eaceev of cuprous giilphido remains un decomposed. IkR-Ullie inm dwom|X>Bea 
eaprous salphidci though very imperfectly, yielding copper containiug iron, iron 



76 



COPPER: SULPHroEa 



contaiiiiitt eoppec, ftnd ntlphide of copper and iron. Ferric oxide exerts but a alight 
d ee ompoauig action, and ferrooB silic&te noiie at alL (Gm. r. ^10 

Pol$§uFpkid€9 of copper, — Ad ftqaeovs aolutioo of {>entanLlphid« of potaannm 
famw, with eapric salts, a Uver-coloured precipitate, coosistijig of Cii*S*, wluch tama 
black aftd* dijmg, ianot altered hj espoovre to the air« or by washiog irith boiling water, 
and when recen^ precipatated diaBolTes in aqaeoua carbonate of potaaaitmi, forming 
a brown aoIiition.*->Tbe dimlpbide, triBiilphide, and tetrs^alphide of potassiam, form 
with cuprie aalta, predpitatea of the same colour, likewise foluble in carbonate of po* 
taasiam, and consisting either of the compoanda, Cu^^ Cn^t and Ca^\ or of niix* 
tnrea of Cu^ and Cn^. (B e rze 1 i n s.) 



Sttlpt&idtta of (Sopper •&(! Ilwtlimmy. a, Wolfihergitt. Antimonitd 
Otfpprr^ ChalcostibiUit^ Kup/trantimonffians. — A mineral oeettmng at Wolfebei^ in 
thenars, and at Giiadix in Spain, in small ajggregated tabttlar prisms of the tri- 
metric ajBtem, exhibiting the faces oP, oe P , (u ^2 . a> J^ oe- Inclination of &oe8 
<»P:obP-10P; a.P2 : oo P2 - 13S^.l2'; 00^2 : » t » - U2« 24'. Clearage 
fery distinet, parallel to oo I* v ; less distiiiet, parallel to oP. Specific grarity 4748. 
H^daess — 3^4. Lustre metallic Streak black. Colonr betwQien lead- and iron* 
grej-. Opaque* Fracture ooncboidaL Before the blowpipe it decrepitateii, fnaes 
readily* and on charcoal gires f^ea of antimony ; after strong heating with soda, it 
yietds a globule of copper. 

Tha mineral la a cuprous sulphantimotiite, Cu^SJb^S*. or ^52 (s*. 









H- Bom. 


Th. Ricbler. 






24-46 


Gitodm, 


Cu» . . 


. . -ii^ 


25-61 


25-36 


8b 


. 120-3 


4856 


46'«1 


48-30 


8« . , 


. 64-0 


2683 


26 34 


u-n 


Iron 


* ♦ . ♦ 


^ ^ 


1-39 


1-28 


Lead . 






0-56 














247-6 


lOO'W 


m-56 


10018 



b, Wotchite. Antimonial Copper-glance^ AntimonkupfergJnne.^^A, mineral occur- 
ring in the iron mines at St. Gertrand. Carinthia, in short rhombic prisms, clearing im* 
SsrfectJy parallel to the brachy diagonal ; also massiTe. Specific gravity 5*7^ — i*94. 
ardnesa ~ 3. Fracture conchoTdal to nnereQ. Brittle. 
The analyses of this mineral difer widely, as tJie following table will show : — 



Sdiriktef. 

Sulphur 28-60 

Copper 17*36 

Antimony . . , , . .16-65 

Arsenic 603 

Lead 2900 

Iron 1-40 

99-93 



Runmelibcrg. 
16-81 15-23 

42-83 43-69 

24-41 24-46 



15-59 

0-36 

lOO-OO 



1615 

100-11 



The mineral is probably nothing but a partially altered Boomomte (i 651). (Ram* 
melsbera, pw 80; Bana^ ii- 82.) 

For ^k^Sulphantimoniteg of copper and iron^ &cu, see TKTBAHxnBmu 

Snlplitdea of C<»pper and Armenie* — None of these compounds occur as 
natumi minerals (im^ 8rLFHAi]LSB?iiT£s njid Sulfhassekates, l 390, 393). In many 
TBri*'lieK of p^y copp^^r the antimony is partly replaced by arsenic. (SeeTmfNAKTiTa.) 

•ulpMdea of Copper asd Slaoiiitla. iz. Tanneniit, KupfemdimitihgUns. — 
Oeenn at TaxmenbaDm^ near Schwafzei^berg in the Engebijgt io thin striated prismt^ 
«|ipanntly trimetnc Lustre bright metalEc. Colour greyish to tin-white. Heated 
in an open tube it yields sulphur* Before the blowpipe on charcoal, it fuses easily 
with intumescence^ and yields with soda a globule of copper. Bissolres in nitric acid 
with deep bluish-men colour. 

Schneider found in this mineral (mean of two aDalyses) 19*83 per cent. S, 62*16 Bi, 

and 18-72 Cu, which agrees very neiirly with the formula Cu^8.BiS\ or S^! [s» (cal- 
culation 1908 S, 62 01 Bi, 1891 Cu). The niinera] is, thcrefbre, analogous in consti- 
tution to Wolfsbergite. (Rammelsberg, p. 103 ; Dana, iL 73.) 

6. Wi tiichenitK Cupreom Bi^muik, Kupferwism utft^jt, — A mineral found in the 
cobalt mines near Witticnen, in Baden, sometimes massive and disseminated, some- 



COPPER: SULPHIDEa 77 

times in coarse colamnar shapes, or aggregates of imperfect prisms (trimetric ?), deav- 
ing in one direction. Specific gravity «= 6. Hardness = Z'6, Colour steel-grey or 
tin-white, tarnishing pale lead-grey. Streak black. Fuses easily in an open tube, 
yielding sulphur and a white sublimate. On charcoal before the blowpipe it decre- 
pitates, melts, forms a yellow deposit, and after reduction with soda a globule of 
copper. Boiled with hydrochloric acid in a flask, without access of air, it dissolves, 
with elimination of sulphuretted hydrogen, to a nearly colourless liquid, a certain 
quantity of admixed metallic bismuUi remaining undissolved. If, on the other hand, 
the air has access to the liquid, the metallic bismuth likewise dissolves after a while. 
Nitric acid dissolves the mineral with separation of sulphur. 

The analysis of this mineral by Schneider (Pogg. Ann. xciii. 305, 472), after 
deduction of the admixed metallic bismuth, gives 19*42 per cent. S, 43*05 Bi, and 

37-63 Cu, agreeing with the formula ZCu'S.BiS*, or ^p'|s«(calculation 19 -50 8,42*98 

Bi, and 38*42 Cu). Other analysts have obtained different results, because they over- 
looked the admixed metallic bismuth (Eammelsberg, p. 104). A grey massive 
mineral found in the Geistergang at Joachimsthal, containing 9*94 per cent S, 30*74 
As, 45*31 Bi, and 13*04 Cu, appears to be a mixture. (Kamm els berg, loc, cit.) 

Sulphides of Copper, Bismuth, and Lead. See Needlb-obb. 

Snlplildes of Copper and Zron. a. Copper Pyrites, Chalcopyrite, lowanitSf 
Cidvre pyriteux, Kupferkies, CuFeS, or Cu^S.Fe*S*. — This mineral occurs in crystalfl 
of the dimetric system, oft^n tetrahedraL The primary form P, for which the length of 
the principal axis is to that of the secondary axis as 0*985 : 1, the an^le of the ter- 
minal edges s 109^ 53', and of the lateral edges » 108^ 40', occurs in the hemihe- 
dral form as a sphenoid (see Crtstalloorafhy), both alone and in combination, as 
in^. 145. Cleavage parallel to 2P oo, but generally in- 
distinct Frequently in twins. It often occurs also mas- Fiff. 145. 
sive and impalpable. Specific gravity 4*1 — 4*3. Lustre 
metallic Colour brass-yeUow, subject to tarnish, and 
oft^n iridescent Streak greenish-black, a little shining, 
opaque. Fracture concho'idal, uneven. Rather sectile. 
It decrepitates when heated, acquiring a darker, colour, 
and sometimes giving off a trace of sulphur. Gives off ' 
sulphurous anhydride when roasted. On charcoal before 
the blowpipe it melts, with intumescence and sparkling, 
to a globule which is dark grey within, black and rough 
without, and is attracted by the magnet The roasted 
elobule gives, with fluxes, the reactions of copper and iron. 
It dissolves in nitric acid, with separation of sulphur. 

Analyses.— a. From Raxnberg in the Sayn district, crystallised (H.Rose). — b. From 
the Fiirstenberg district, crystallised (H. Rose). — c. From Orryarfvi, Finland (Hart- 
wall). — d. English ; a crvstallised, /3 botryo'idal. — e. AUevard, D^partement de 1' Isire, 
massive (Berthier).— /. From Kaafjoid, Norway (Malaguti and Durocher). — 
g. Val Castrucci, Tuscany. — A. Monte Catini, Tuscany. (Bechi.) 






a 


h 





a 


/3 


e 


/ 


9 


h 


Sulphur 


35*87 


36-52 


36-33 


3516 


34-46 


36*3 


38-76 


35*62 


3616 


Copper. 


34*40 


8312 


32-20 


3000 


31*20 


32-1 


32-73 


3409 


32-79 


Iron 


30*47 


3000 


3003 


32*20 


30*80 


31-5 


28-51 


30-29 


29-76 


Quartz. 


0*27 


0*39 


2*23 


2*64 


1-10 


. 


. 


. 


0-86 



101-01 100-03 100-79 100*00 97*56 99*9 100-00 10000 99-56 

The formula CuFeS requires 34*59 per cent Cu, 30*52 Fe, and 34-89 S. 

Copper pyrites is the principal copper oro in the Cornish mines, where it occurs 
associated with tin, purple copper, copper glance, galena, grey copper, and blende. 
The Cornwall copper pyrites is not, however, a rich ore, rarely yielding 12 per cent, 
generally only 7 or 8, and sometimes only 3 or 4 per cent of copper. If of a flne yel- 
low colour and yielding readily to the hammer, it may be considered a good ore ; but 
if hard and pale yellow, it is poor, from admixture of iron pyrites. The copper beds of 
Fahlun in Sweden are also composed chiefly of copper pyrites, which occurs there in large 
masses, surrounded by a coating of serpentine and imbedded in gneiss. It occurs also 
at Rammelsberg, near Goslar in the Harz ; at Freiberg, in the Bannat ; in Hungary ; in 
Thuringia ; in &x>tland, in Kirkcudbright, Wigtonshire, Perthshire, and Invemesshire ; 
in Tuscany ; South Australia; and at numerous localities in the United States. 

Copper pyrites is distinguished from iron pyrites, which it somewhat resembles, by 



78 



COPPER: SULPHIDES. 



itfl inferiOT hnr^oess; it may be cut with tbo Icnife, while iron pyrites strikpa fir© with 
steel It diifc'ra from gold in being brittle ajid attiicked bj nitric acid. 

Cop[M?r pyrites changes to cupric sulpbute on exposure to moiptiire, especially if 
heat^ ; it is aomf times also altered to malachite, coTellin, chiysocolk, black copper, 
coppcr-glaiiee^ mid omde of iron. 

h. Purple Copper, Erube^te, Vafiegatfd Copper^ Liver-coloured Copper Ore, 
Phillipjtiit, Bornitf {Bunthipferers, Buntcr Kupferlaies, Cwiwrtppiteux kkpatiquf). — 
This mini ral forms crystals belonging to the monometric or regiolmr eystem, uamelyi 
the cube, octahedron, rhombic dodecahedran, and intermediate forms. CleftTRge 
octahedral^ indistinct Twin pryst-als are of freqnent occunponce; also nnperfect ctja- 
tallisationa^ with granular strongly connected atmctufc. Specific gniTity = 4 '4 — 5003. 
Hardness = 3. Lustre metallic; Colour between copper-red and pinchbeck-brown, 
quickly acquiring a parti-coloured tamisb. Streak pole greyieli black, slightly shiniMg; 
Fracture amaU eonehoidal, tmeven. Brittle. 

Purple copper does not give off sulphur when ignited in a test-tube, but when heated 
in a tub** open at both end»„ it yiehiii a lai^e quantity of aulphurous anhydride, but no 
flubUmate. Heated on charcoal before the blowpipe, it acqnirea a dark tAmish, then 
becomea black, and red on cooling. AX a somewhat stronger heat, it melta to a 
brittle globule, which becomes magnetic after sufficient blowing, and appears greyish- 
red on the fractured surface. WUen roaste^l for a considerable time, and then treated 
with a fsmali quantity of bonut, it yidda a button of copper, and if fui^ed with carbonata 
of sodium after the uulphur ls completely expelled, it yields separate granules of copper 
and iron. After roasting, it exhibits with fluxes the reactions of cwprie and feirio 
oxidea. When moistened ^ith hydrochloric acid, it coloura the blowpipe fiame blue. 

Ther« aro several varietiea of purple copper. liammelaberg {Mineridchmde^ 
p. 114) airanges them in three groups, containing respectively from 56 to 56 per cent^ 
60 to 64 per cent, and 70 per cent copper, 

1. Purple co|jper, containing from o6 to 68 per cent, copper. — a. CryBtallised, from 
the Condurra mine near Cambern, Cornwall, b. Crystallbetl, from Redruth, in Cornwall 
(C h adn e w). c. Crystallised, of unknown origin ( V ar r e n t r a p p). d. MiiBsiTe, from 
Monte Cattini in Tuscany (Bee hi), e. Massive, from the Miirtenberg mine, DtUamei 
Sweden. (P latin er.) 





a. 


k 


c. 


d. 


e. 


Snlphnr 


. , 28'24 


26-84 


20*&8 


2492 


25-80 


Copper. 


• 56-76 


6789 


58-20 


6688 


6610 


Iron 


. 14-84 


14-94 


1484 


18-03 


17'36 



09-84 



U9-07 10002 98'83 



99-26 



2. Containing from 60 to 64 per cent, copper. — f. From Ferriccio in Tnscany 
(Bechi). g. Fn-^m Miemo in Tuscany (Bechi). A, From Coquimbo in Chili 
(Bocking). L From Kosa Island^ Killamey (Phillips), j. From St Panerace, 
D^partement de TAude (Bt^rthier). k. From Bristol, Connectieut (Bodemann). 
/. From tbe Wortzkiseh mine, on the White Sea (Plattner). m. From Vestanfbwt 
Kirehspiel, We^tmanland, Sweden (Hi singer). ». From Siberia, (R Br an das.) 





/- 


g. 


k 


i. 


i- 


it. 


I 


m. 


n. 


Sulphur 


24-70 


2S-98 


26-46 


2375 


24-0 


26"70 


2606 


24-69 


22*44 


Copper . 


6001 


G016 


6080 


6107 


62-3 


62*70 


63*03 


63*33 


63-86 


Iron 


1589 


1609 


13-67 


14-00 


13 7 


U-63 


11-66 


11*80 


13'2l 




10060 


99-23 


09-93 


98-82 


1000 


99-93 


99-66 


99-82 


9951 



22-3 

700 

7-0 


20-0 

70-0 

7-9 


22'5S 

71*00 

6*41 


99^3 


97"9 


09*99 



3. ConfainingTO per cent, copper.-^ o. From Eisleben (Plattner). |>, FromMonts 
CsJitelli, Tuscany, q. From Nadaud, France (Be rthier), r. From aongershansen, 
near Eialeben. (Plattner.) 

o. 

Sulphor . . . , 22-66 

Coppiir .... 69-72 

Iron . , . , * 7*64 

99*91 

Rammelsberg regards the sereral varieties of purpU eopper as isomorphons mii- 
tarea of the compounds 3Cu*S.Fe^8', and wCu*S.Fe*S, It n ^ 0, this fonnula is 
reduced to 3Cni*S.Fe*S', wbieli requir^^s 28'04 per cent B, 55*60 Cii, and 16*36 Fo, 
agreeing nearly with analyais a of the mineral from the Condurra mine. Any ralue 
of « greater than 2 increases the proportion of copper ; n = 3 gives 25'67 per cent. S» 
60'85 Cu and 13 48 Fe, which is very nearly the composition of the minerals A, i, J; 
and » - 11 requires 22-62 per cent S^ 7«>*40 Cu^ and 6-68 Fe, which is nearly the 
composition of tho specimens o, r. 



COPPER; TELLURroE— BASES AMMONIACAL, 



79 



Pniple copper occurs associated with other copper ores. Crystalline varieties are 
found in Cornwall, mostly in the mines of Tincroft and Dolwath, near Redruth, where 
it is called by the miners " horse-flesh ore." Massive varieties are found in Roes 
Island, Killamey, in the cupriferous shale of the Mansfeld district, also in Norway, 
Siberia, Silesia, the Bannat, and in PennsylTania, New Jersey, and Connecticut. 

c. Cuban. This mineral, found at Barracanao in Cuba, is also monometric, occur- 
ring in cubes ; also massive. Colour between bronze and brass-yellow. Streak, dark, 
reddish, bronze, black. Specific gravity = 4-026 (Breithaupt) ; 4*169 (Booth). 
Hardness = 4. Melts easily before the blow-pipe, giving off fumes of sulphur. The 
following analyses have been made of it (deducting silica) : 

Scheidchauer. Eastwick. Stevenf. Magee. 

Sulphur 3478 39-93 4011 4019 

Copper 22-96 2026 21-46 20-71 

Iron 42-6 1 3890 89-66 3941 

100-25 9909 101-12 10031 

The first analysis agrees nearly with the formula Cu'Fe^S*, or ^-p 20 [ Fe^S*, which 

requires 35-38 per cent. S, 23*38 Cu, and 41*24 Fe ; the others, which contain a much 
larger quantity of sulphur, approach more nearly to the formula Cu*S.Fe*S*, which re- 
quires 42-21 S, 20*84 Cu, and 36*94 Fe. (Rammelsberg, p. 118, Dana ii. 681.) 

d. Copper regulus. It has already been mentioned that the reguli produced in 
copper-smelting consist essentially of cuprous sulphide, Cu^S, associated with sul- 
phides of iron (ii 27—31 and 34, 36). Field (Chem. Soc. J. zv. 126) regards 
all copper reguli as compounds of cuprous sulphide in various proportions with 1 at 
Fe*S», 1 at. Fe*S, and 2 at Fe*S. The following table exhibits the composition of 
some samples of furnace reguli at different stages of the smelting process, as compared 
with this theoretical view. The first is clean regulus from a furnace ; the second is 
the same after some hours roasting ; the third the same after further roasting and 
skimming. The fifth (with 8 at Cu*S) is a specimen of native blue sulphide. 

Composition of Copper Regulus. 



Salphur 
Copper . 
Iron 


With 3 ai. 
Cu^S. 


With 5 at. 
Cii^S. 


With 6 at. 
Cu<S. 


With 7 at. 
Cu<S. 


With 8 at. 
Cn<S. 


With 12 at. 
Cu^S. 


Calc. 


Exp. 


Calc. 


Exp. 


Calc. 1 Exp. 


Calc. 


Exp. 


Calc. 


Exp. 


Calc. 


Exp. 


27 06 
3609 
36-84 


27 08 
36-12 
36-78 


S.V43 

46-24 
88 32 


?5-27 
49 34 
28-19 


24-86 
49-74 
26-38 


24fl5 
49-71 
'26 34 


24-41 
.W-57 
23-00 


24-32 
52-48 
22-89 


2403 
54-93 
21-02 


24*12 
54-21 
21-13 


23 00 
61-34 
15-65 


22-90 
6I-;J4 
15-61 



COVFSSy TBULVSZBB or. Pale red compound. (Berzelius.) 

COVPBXf xmrGSTATX or. Found native in a mine in Carrabas County, 
Nort h Carolina. (D a n a, ii. 602.) 

COFPSR* VASABATX Or. Occurs native, as Volborthite, in Siberia and 
Thuringia. Vanadates of copper and lead are found in the Lake Superior region, and 
in Chile. (See Vanadates.) 

COPPBX* VASZaaATBB. Syn. with Pxthfle Coffbb (ii. 77). 

COPPBXf VZTSBOV8. Syn. with Copfeb-olancb (ii. 74). 

COPPBR-BA8BS, AMMOmACA^. The ammonio-chlorides, iodides, oxides, 
&c., of copper already described, and likewise certain ammonio-copper compounds con- 
taining sulphuric and other oxygen-acids, may be regarded as salts of ammonium- 
molecules, in which the hydrogen is more or less replaced by ammonium and by cu- 
pricum, or cuprosum, thus [Am = NH*] : 

1. Chloride of Cuprammonium) i^8(^ci 

(ii.63) . . .J * 

2. Sulphate of Cuprammonium 2NH'.Cu*S0* 



3. Sulphate of Cupricum and) j^jp (^«go« 

Cuprammonium • . •> 

4. Chloride of Ammo-cupram- ) 

moninxn . . • • ( 



2NH».Cua 



- (NH»Cu).a 

^(NH«Cu)')q. 
"" (SOT 5" 

NH«Cu) 

Cufo* 
(S0«)") 

« N(IPCuAm).a 



80 



COPPER-BASES, AMMONIACAL. 



5. Iodide of Ammo-cupram- 

iDoulum + 

6* Bromatti of Anxmo-cupram- J 

mouiani 



":1 
1 
1 



8. 



9. 



10. 



:! 



7. Nitrate of Ammo-cupium 
monium 
Hydraf^ of AraiDo-cupram-> 
mooium . < .( 

Hyposulpliate of AnunoJ 

lodidfl of Ammo-cuproa- J 
ammonitiin . 
IL Hjdrate of Ammo-tricu 
prammoniiim 

12, Chloride of Dmmmo-cu- J 

pnimmooium (ii. 53) .} 

13, Sulplmto of Cupricuin imd) 

Triammo^caprammoiiiuiii y 

Bromide of Animo*dicu- ) 
pn>-diammonimn (ii 52) ( 

Bromitlo of Triammo-dicu- i 
pro-diammonium (ii. 52) { 

Sulphate of Triammo-dicu- j 
pro-diammoDium . .( 



14 



15 



10 



2NH».CuI 
2NIP.CuErO» 



2NHlCaN0« 



4NH*.CuK) + 4H»0 



4NH»,Cii^SH}- 
2NH".Cii1 

4im».3Cii^ + eH»o 

SNn^.CuCl 



4NH«,Cu*S0^ -I- H'O = 



3NH*.2CuBr 
5NH^2CiLBr 
6NH-.Cu'S0* 



^ N(H*CQAm).I 

__ N(H^CiiAra)(^ 
(BrO«)i" 

N(H*CuAm)frt 
(NO")'r 

^[K(HK?nAm)PJ0. 
«N(H^cuAm)J 
.2(^(^'^^J0) + 7aq. 

-.N(HCuAffli«).Cl 

^^'""VAm*)) 

CnfO' + aq. 
(SO')') 

= [N«(H«Cu»Am)f.Br» 

=-[NXH«Cu*Am*)]^Br« 
_[NXH'Ca'Ain-)]"(o, 



PentammoniO'eupric Suiphaift or Sulphate of Triammo-dicupro^di- 
ammoniu m, 5NH'»Cu'S0*, is produced when anlijdrousciipric sulphate ia exposed to 
the action of dry ammonio^gas, rapid absorption then taking place, attfiided with rise 
of temperatore and tumeftiction. The product is a blao powder, whi(?b melts it i 
moderate red heat, ginng off a lai^ge quantl^ of ammonliit together with water and sol* 
phite of ammoniom, and leaving cupric sulphate mixed with metallic copper. It dia* 
Bolres completely in water, foimiiig an azore-blue solutioQ. (Bammelsberg, Pogg, 
Ann. JOL 160.) 

Teirammonio-cupric Sulphate, or Sulphate of Cuprieum and Triam' 
m o 'C It pr ammonium, 4NH*.Cu^S0* + H'O, also call<?d (htproenlpkate of ammonia^ 
Cuprum aminoniacide, Kupfermlmiakt ia produced by tneatin^ cryst^illised cupric eul- 
phatc, either pidTorised or dissolved in water, witti ammonia, till the precipitate is 
completely redissolTed. It crystallisea bj evaporation, or better, on carefully oorenng 
the itoltition with a layer of alcohol, or exposing it to a low teiiip«iiiture^ in long thin 
priamatic crystals of the trimetric system, transparent^ and of dark axure-bhie colour; 
On agitating the ammoniacal solution with alcohol, the salt is precipitated in the form 
of a blue crystalline powder. It must be quickly dried between bibulous paper, and 
kept in well dosed vcssel^u It dlasoWea in 14 times itA weight of cold water. Wben 
ej;p084*d to the air, it gives off ammonia and leaTPS a green powder, whitjh appears to 
be a mixture of sulphate of ammouium and tetrabaaic cupric sulphate, Cu*S0'',3Cu*0. 
When heated for some time to a temperature not exccading 149^ C, it gives off 2 aL 
ammonia and 1 it water, and Jeaves sulphate of caprammonium : 

4l^H".Cu'«0^ + H*0-{2NH* + H^) = (NH»Ou)'.SO*; 
and this residue graduaUy heated to 205^ C. gives off another atom of ammonia, leav- 
ing sulphate of cuprieum and cuprammonium, {NH'Cu).Cu.SO* : and this Again, it 
gradually heated to 2r*0° C still givfia off 1 at. ammonia, and leaves moutnil sulphate 
of coppto", Cu'^SO** The aqueous solution of the tetrammonio-cupric salt when ex* 
posed to the air, di»poaita tetrabasic cnpric aidphate, which is likewise precipitated 
when the sttlutiun ia largely diluted with water. Zinc qtdcklj precipjtat<» me- 
tallic copper ham the solution ; cadmium and lead decompose it more slowly ; arsenie 
decomposes it completely, forming cnpric arsenite ; bismuth, antimony, tin, and iron 
have no effect tipon it. (Qm. v. 449,) 

Netttrai Sutphate of CnprammoniuTjt, (NH'Cu)',SO^ obtained as above stated 
by grfwiuaEy heating the precfiding salt to 149*^ C. ia an upple-grcen powder, which, on 
ezposnro to the uir, absorbs water and turns blue. If moi9t*^ned with a small quan- 
tity of water, it becomes very hot, and turiifl blue immediately. An cjicess of water 
decomposes it into sulphate of ammonium, tetrammonio-cmaric sulphate, and tetrabasic 
capric sulphate : 

^(N'HKhi^O*) + 4HK) ^ SN^H-SO* + (4NH».Cii*S0^H*0) + (Gu*S0\3Cu*0). 




COPPER-FROTH — COPPER-MIOA. 81 

Sulphate of Cupricum and Cupr ammonium, NH».Cu*SO*, or ^^^^^| SO*, 

18 tlie residae obtained bj gently heating anhydrous cupric sulphate saturated with 
ammonia, or by gradually heating tetrammonio-cupric sulphate to 149° C. (Q-m. 
T. 460.) 

DiammoniO'Cuprie Nitrate, or Nitrate of Ammo- cupr ammonium, 
2NII'.CuN0*, is obtained by saturating a hot concentrated solution of cupric nitrate 
with ammonia-gas, and leaving the solution to crystallise by cooling. It forms blue 
needle-shaped ciystalfl, which give oflf a little ammonia when heated, but no water if 
it has been previously well dried. At a higher temperature it explodes. It dissolves 
easily in water ; a small quantity of acid added to the solution urows down a basic 
cupric nitrate. (Gm. v. 456.) 

Br ornate of Ammo-cupr ammonium, 2NH'.CuBrO*, is precipitated in dark 
blue needles aind as a cxystalline powder, on adding alcohol to an ammoniacal solution 
of cupric bromatc. It turns green when exposed to the air, dissolves in a small quan- 
tity of water, but is decomposed by a larger quantity, with precipitation of cupric 
hydrate. (Gm. v. 463.) 

The corresponding iodate is formed in a similar manner. 

Tetrammonio-cupric Hypoeulvhate, or Hyposulphate of Ammocupram- 
m on turn, 4NH'.Cu*S*0*, is produced by supersaturating a somewhat dilute solution 
of cupric hyposulphate with ammonia. It crystallises in azure-blue rectangular tables, 
permanent in the air, sparingly soluble in water. (Gm. t. 448.) 

The following salts have lately been obtained. 

Silicate of cuprammonium (NH*Cu)*Si'0* 

Tungstate of cuprammonium (NH*CuyW*0« + WO 

Metantimonate of cuprammonium .... (NH*Cu)*Sb-0^ + 4H*0 

Pyrophasphate of cuprammonium . . . . (NH'CuyP*0* + H*0 

Orthophosphato of cupricum and cuprammonium . (NH*Cu)*Cu.PO* 

Arsenate of cuprammonium (NH'Cu)^.AsO« + H*0 

Acetate of cuprammonium C«H*(NH»Cu)0» + H'O 

Tartrate of cuprammonium C5*H*(NH*Cu)*0« 

Tartrate of ammocuprammonium .... C*H*(NH*AmCu)K)* 

Succinate of ammocuprammonium .... C*H\NH*AmCu)0* 

Anisate of ammocuprammonium .... C*H'(NH'AmCu)0»+ H*0. 

Thew salts are obtained either by saturating cupric salts with ammonia, or by de- 
composing monammonio-cupric sulphate, NH'Cu^SO*, with barium salts. 

Ethylaminc seems to form cuprammoniums of analogous composition. (Hugo 
Schiff, Compt. rend. liii. 410 ; Ann. Ch. Pharm. cxxiii. 36.) 

COnSR-TSOTB. A basic arsenate of copper, Cu*AsO*.2CuHO + J aq., also 
called Tyrolite and Pharmacoeiderite, found native at Falkenstein in the ^tytol, and 
other localities. (Sec Ttbolite.) 

COPVZB^OZhAJrCB. Native cuprous sulphide (ii. 74). 

COPyirW^OTi a WCa, AVTZMOirZAXi. (See iL 76.) 

COVFSSy OSSSVf or Chryeocolla, A native silicate of copper, Cu^iO' + aq., 
occurring in Cornwall, Hungary, Siberia, South Australia, &c., and used aS' an ore of 
copper. (See Shjcates). 

COPPaB»BfZCA« This term is applied to two very different substances, viz. : 
\. A native arsenate of copper of somewhat variable composition (Cu*AsO*.6CuHO + 
xaq.), also called Tamarite and Chalcophyllitc. (See Tamabitb). 

2. A cuprous antimonite, 3Cu*0.Sb*0*, or Ccu'SbO*, which is sometimes found in 
refined copper prepared from antimonial ores, and renders it more cold-short than red- 
short. When copper of this description is dissolved in cold or slightly warmed nitric 
acitt the cuprous autimonite is left behind, in very thin, regular, six-sided laminae, 
tranjilncent, having a gold-yellow colour, and becoming brown and opaque while hot 
In the flame of the oxyhydiogen blow-pipe, they melt to a black-brown glass. With 
borax they exhibit a slight intumescence, and form a yellowish -brown glass, turning 
greenish-blue when mix^ with nitre. Strong hydrochloric acid dissolves them more 
completely than any other acid. The compound gave by analysis (deducting small 
quantities of lead, silver, iron, silica, and alumina), 67*68 per cent Cu^O, and 42*32 
SVO* (calculation, 68*64 Cu*0, and 41*16 Sb*0*). (Hausmann and Stromeyer, 
Schw.J.xix.241). . ^ 

Copper-mica, nickeliferouM (7CuH).6Ni»0).SbK)»? This compound is obtained 
from copper smelted at Ooslar. After the copper has been treated with dilute nitric 
ari«i the copper mica is freed from arsenical oxide of antimony — proceeding from 

Vox.. IL G 



82 



COPPER-NrCKEL — COPKOLITES. 



antimooide of cctppt^r prGYioiiidjr contAincd in the copper^ and decomposed by the nitric 
acid — by digesting it in a mixture of hydrochloric and tiirtaric ucid. In tliis mftnner 
100 p&vts of kigUj micaceous copper yield 4" 16 pts. of pure ex)pj>er-miea* It forma 
pule greenish -yellow, tranaliiceut, strongly lustrous, regular six-aided laminxT, which 
iLSsume a tratisi^nt yellow colour when heated. This compound neither fuses nor 
Bnifora any alteration at a red heat. With carbonate of «oda on charcotvl, it yields jn 
white brittle metal* and coven the chajcoal with antimonic oxide. Heated in the 
outer blowpipc'fiame with borax or microcoemic aalt^ it dissolves immediately, and 
forms a light green ^lass. It is acarcelj attacked by acid% excepting by eoncea- 
trated hyditjchloric acid, which dissolves it after long boiling. When hydrogen gaa is 
passed oT«r 100 pts. of red-hot copper-mica, a quantity of water ia obtained corre- 
sponding to 1 8" 19 per cent of oxygen* (In this reaction 2 '5 5 pts, of the mica^that 
whith contains only nickel and no copper — appti-ar to escape decompcksition.) The 
reaidue is baked together, but still retains the form of lamina? ; it may be decomposed 
by nitric acid or by chlorine i in either casaj the pure nickel-mica remains midecom- 
poaed. 

Nickelifeiroiis copper-mica giyei by analysis (abstracting the niekel-mica) 44'28 per 
cent. Cn*0, 30 61 NiH3, and 2511 Sb»0", the above formnla requiring 45 13 Cn-O, 
3il"21 KiU and '24 06 Sb-O". (Boncber, Fogg. Ann. xli. 335.) 

CimBR»irXG£B£. Native ars^enide of nickel (See Kicksl,) 

CO^P&&-PTKXT£S. (See Suu'HEDEfl of Coppma aud luottf iL 77») 

GOPFHIULS^ Protosulphate of iron, (See StrLPHATSS.) 

COFROltZTfiS. The excrements of extinct animals, found in lli^ quantities in 
certain gt?ologif?al formations, especially in the lias. Their true nature wa» first 
piiinted out by Buekland. They consist mainly of phosphate and CArbonate of cal- 
cium, the miontity of phosphate sometimes amounting to between 80 and 90 per cent. ; 
they contain atio mogneiia, oxide of iron^ Bilica, water, and organic matteTt with small 
qnantities of manganese and fluorine. Their composition ia, in ^t, rery much like 
that of bone^ the honj constituents of tbe excrements having nested the action of de- 
composing agents more than the other portions. The quantity of phosphoric acid in 
coprolites renders them very valnable as manure, 

Analysf^ of Coprolites, 





T. J. H»jL4?*Ta (■>. 


T.H.Kv»rr{b). 


Ojmta |c>. 


a-n«t<t). 


Wotr»(»^ 


tAW* it) 


lf*VqTtC»- 








mm 


Prora 


Vnm 


LiRnttc 


Pramllw 






Fvnn Um Lover 


mn. 






Cb«lk 




FKrm tli« eoHt orSuSbUc 


&lu4Kit wtrtt^ 


in* Vi^H^ 




r^. 


A(rth.la 


MCW 






«rc«u4s. 




Mill* in 


tb« 


RnhH, iB 


Phoiphoric wilijrilrldo . 






vUtV 


Bohrailji. 


TmU*. 


•tsr 


KrMit.. 


















. 


2443 






tl-S9 


PtuMphHieofcftlclmn 


























C^apO* . . . 


jm 


ta-8e 


60-t 


67*53 


40^34 


363*4 


44'70 




. 


tb'E 


4&aft 






traro 














30-60 












16 


<7J 


, 


. 


. 








, , 


m 


a-04 




Ferric phoipkiatt . 
riiiorfJenrcjdcruTn 


era 


!>a 


<*I 


■ . 


. 




, 




. 


. 


2771 




061 


17 






















Cftrbqnlic Biibjdridu. 


, 




, 


, 


■ 








ia-s& 


^ 


7-6» 


17*50 


CarbonAle tU calci urn 


lOJfl 


V.I 


237 


4-34 


5H 


BtK> 


Gm 


34-77 










Curbonate wf niB|ri»r4Vuin 


trace 


O-B 




i-e-s! 


!>70 


J7-02 


i 4 7« 




, , 


4*4 






Froto9,ki]o or troo . * 


. 


. , 


* « 


ar9S 


laea 












Lime .... 


. 


* ■ 


, 


» , 


. 


. 






40-70 


, 


I'M 


50-SO 


MAgiifiln .... 
Se«i|Uku«id« of Iron , 


• * 


I* . 


's-o' 


. . 


• - 


* ' 


* - 




fttJS 


|.o 


1 tn% 


|3^ 


Alumina . 




6-a 






















SieMiuto&kde of maDganeie 


trace 


. 


• 


. 


. 








. 


. 


, , 


4*10 


BlUcA .... 


^7y 


10« 


pfi 


. 


. 


. . 






, 


97 






tUnd. . . . . 




* 


. 


ai'jo 


2&J4 


4990 


37 90 


13' 10 


• 


13-7 






a u] phake or calel um 


trace 


, 


I-S 










17a 










Su]phate of potAkalum . 


- 


. 


, 


» , 


, ^ 


. . 






, , 


&-a 






Chluridf of iodluin , 




. 


. 


. 


^ 






0*80 


7-&S 1 








Soluble laltt . 


trace* 


trncci 


tr*c« 




















W-ter . . » . 
O reran Ic matter 


*Wt 


um 


&1 


JiS 


S-Il 


1-7 


a 00 


7-30 


♦ , 


» 


7*50 


I'M 


Urftte of unmoDium and 


























lime .... 


. 


. 


. 




. 


. 


. 


a-oo ' 


. 


. 


a-aa 




lOOOB 


99"87 


lOOi 


9971 


5537 


lOOOO 


S7-W* 


too-0* 


lootw 


U7h 


iQOtK) 


da2p 



* Ann. Cb. Fliam), IswU. L 
e Fogg, Ann, ev. 15&, 
Stll Am 



f Wleo. AkAd, 



J. m «v, 

LAd. B«r. 



Hf IIL 124. 



ii HiJd.ixiEixssj. 

<* Cbetsi. Oai. 1849, 4*r>. 
f jAlirb, Mirier. 184T, 729. 



COPULA— COBACITE. 



83 



The chalk marl and adjoining strata are also very rich in coprolites and other pe- 
trifiictions containing phosphoric acid, as shown by the following analyses made by 
Messrs. J. M. Paine and J. T. Way (Joom. Boy. A^. Soc. vol. iz.pt 1) : 

a. The chalk marl with fossils containing a large quantity of phosphoric acid. 
6. The mari itself from which the petrifactions have been separated by siftmg. c. In- 
durated marl and small fossils which remained on the sieve, d. Marl from Bentley 
with the fossils, e. The fossils therefrom. /. Petrifactions in the npper marly layer 
of the Upper Oreensand. ff. Soft amorphous bodies in the same. A. l^etrifactions in 
the Gaulty very rich in phosphoric acid. i. Petrifactions at the junction of the Gault 
with the Lower Greensand. k, A conglomerate of petrifactions with sandstone cement. 
L Oreen granules from the Lower Greensand. 

PetrifaeHoM in the Chalk Marl and a^oining Strata, 







a. 


fr- 


Ci, 


if. 


r. 


/* 


!J7'13 
17-18 

t-49 


A. 


^. 


*. 


j; 


liBMI . 


n - 


lira 
MSft 

37 71 

\-^ 

98M 


1 I'M 
U-4G 

1^ 


d-31 
3fi-30 

1341 


'327 
7M» 

3-04 


14 SS 
47 4(J 

lliO 


®»7 

a-77 

|7^ 
42'^ 

car 

4 M 


I^fi4 
&'e4 

75'46 

Lit 
a- 5© 

2*30 


43«7 
3-40 


4 S$ 

g-ll 
IN 

4" 12 


30^^ 
4-D! 
613 

1 18"69 

C0-9<* 
J 7^ 

179 
1 1*7 

3-29 


JHumbu 1 ■ 
firiqiiiDXiida oT Iron 

Sods . 

W«L«r, «fi«ii ic matter 


Alio. 






10D15 


i^'21 


100^ 


ICMHIO 


lOUOO 


100 36 


99^&1 


90-96 


97 SI 


£»7-l4 



See C0NJTJOA.TED Compounds (iL 8). 

<MIQ,inMBlT& White Copperas, — ^A hydrated ferric sulphate found in the dis- 
trict of Copiapo in the province of Coquimbo, Chile, apparently produced by the wea- 
thering of iron pyrites. It forms crystals belonging to the hexagonal system, namely, 
tmaU six-sided prisms with truncated pyramidal summits, 00 P . P . oP. Angle of the 
terminal edges » 128° 8'; of the lateral edges « 68°. Clearage imperfect^ parallel 
to the prismatic faces. Also in fine-grained masses. Specific gravity » 2 — 2*1. 
Hardness » 2*26. Colour white^ inclining to brown, yellow, green, and sometimes 
Une. Lustre vitreous. Transparent or translucent. Taste astringent Before the 
^wpipe it first gives off water, then sulphurous acid, and leaves a residue of ferric 
oxide. It dissolves in cold water and in hydrochloric acid, leaving only a small quan- 
tity of silica. The aqueous solution deposits a laige quantity of feixio oxide on 
boiling. 

Analyses by H. Bose (Pogg. Ann. xxviL 310) : 

S0« Fe*0« A1*0« CaK) MgH) SiO« HK) 
Ciystalline . 43*66 24-11 0*92 0*73 032 0*31 30*10 « 100*04 
Granular . 4366 26*21 0*78 0*14 0*21 0*37 29*98 - 100*24 

Tbew analyses agree nearly with the formula : 

FeH)«.3S0« + 9H«0 - Fe*(SO*)« + 9H»0, or/e«SO* + 3H>0 ; 

[if /« -i |Fe - 18|], which requires 42*7 SO*, 28-5 FeW, and 28*8 water. 

The same salt has been found, also in hexagonal crystals, by Scacchi in the Phle- 
gnean Fields, together with Halotrychin. Bammelsberg (Mineralchemie, p. 274) 
also regards as coquimbite, a mineral from Coquimbo, formeriy called Blakeite, 
analysed by Blake (Joum. Bost Soc. Nat Hist.), and found to contain 41*37 per cent 
S0». 26*79 FeH)!, 106 A1*0«, 0*30 MgH), 0*82 SiO«, and 29*40 water, which agrees 
nearly with the preceding formula ; but it crystallises in regular octahedrons. Dana 
suggests that it may be an iron alum. 

COMAOVTMi A mineral found on the north coast of Lake Superior, where it 
forms beds 2 inches thick in syenite. It is amorphous, with rough, conchoidal, 
resinous fracture. Colour black with gprey streak. Specific gravity 4*378. Hard- 
ness 4*6. Heated alone before the blowpipe it remains unaltered ; with fiuxee it gives 
the reactions of uranium. It appears to be a variety of pitchblende, in which the 
vanic oxide is portly replaced by alumina (Leconte, oilL Am. J. [3] iiL 173; 

o2 



84 



CORAL — CORI ABIN. 



Jahreaber. d Cbeiru I 18i7-48, 1167). An analyais bj Whitney (SilL Am. X [2] 
Til, 434)gaTc: 



TJ*0' 


A1^0» 


Fe*0' 


Pb*0 


Ca^O 


C0» 


SiO« 


HO Total, 


6930 


090 


2-24 


636 


1444 


7-47 


4*36 


4-04 * 0870 



CO&JilL* Coral rocks eousist mainly of carbonate of calcium, with rariablfl 
qnantitit^s of carbonato of magncs^ium and organic matter, and smaU quantities of 
pbotiphivt**, tinlpbate, aod fluoride of calcium, altailine chlorides, 03tidc of iron and 
tilica. Silliman found in fresh corals only I per cent, of roagneaia, but in dcoeo coral 
rock the carbonate of uiagncsiuni waa found to amount to 38 07 per cent Another 
rock, oonsieting of the d^d>m of corals contained 629 per cent carbonate of magnesium. 
The presence of the magnesia appears to be due to^ a double decomposition taking 
I^oe between the original carbonate of calcium of tie rock, and the magne4«ian salts 
in 8ea-water» a ppoc*!ss which likewise contribute to the hardening of the rock. 
(Jahreibcn d, Chem. 1847—8, 129L) 

B. Silliman, jun. (Sill Am. J. [2] xil 174), found in a considerable nuni'^ier of 
reef-forming eondfti, from 2*11 t^ 9*43 per cent organic matter; the residue left after 
the removal of this contained from 97 to 09 per cent carhonate of calcium, together 
with soluble silica, lime probably in combination with Bilica, alao carbonate of magne- 
gium, and the other salts alxive-mentioned. 

The red pigment of eorals Is, according to Trommsdorff, not ferric oxide, but a red 
rc«ln soluble in oil of turpentine, and aftrr r< moval from the coral by this solvent 
eai«ily soluble also in ak^ohol and ether, but insoluble in caustic potash. In a ivd 
mafLrrpore, Vauquelin found a red colouring matter, which was turned Tiokt by 
alkalis. 

The organic matter at the etemfl of polypes appears in some caaos to conjdatof ehititi 
OT concbiolin. 

In QfT&mum noMlf-^ Forclihammer found 2'13 per cent, in Ms ftippmiieSf $'32 
per cent* carbonate of magnesium. In Ct^ralHum rubrum and Madrcpora aculata^ 
Stnitingh and Fyfo found a trace of iodine. 

Respecting the composition and alterations of coml rocks, eee also Dana (Sill. Am. 
J- [2] Ti. 268V Forch hammer (J. pr. Chem. tlWx. 62; Chem. Qaz. 1849, 411.)— 
B amour (Ann. Ch. Phys. [3] xxxii. 362). Buna {iUd, 410). — Alfo Jahresbcr. 
d Chcm, 1847—8, p. 12Q1; 18I&, p. 813 ; 1861, p. 866; 1862, pp. 958— 9GL 

f?1?y II TitiTW II 0FFZCOrA£XS, Nodtthiria oJHcinalts, Muse us eoralltfim f. 
warimis^ — ^Tho ehell of a marine radiate animal, formerly used in medicine. Accord- 
ing to an analysis by BoDTier( Ann, Cliim. viii. 308), it consiats of 61 6 per cent, cjirbo- 
Hftte of calcium^ 7'4 carbonate of magnesium, 03 gypsum, lO ehlondo of sodium, 
0*2 ferric oxide^ 6'6 gelntinous matter, 6 4 albumin, and ppol.>abl^ also iodine and 
IjKwnlnft, It was MseA comminuted and mixed with other corals^ \m, C./ra^ifissima, 
C. cyUndrk4i^ C. moniformM, &e. 

COBBlEmXTS. BjT^. with DioHnoyTB, 

CORI.AJn>EK, OZ£ or. (Tromm8dorff,ArckPharra.[2]ii. 114.-^Kawalicr, 
J. pr. Chern. Ixviii. 226.)— Coriander seeds, the fruit of C&rmndmm sattintm^ contain 
about 0-37 per cent, of a Tolatile oil, besides Ikt, extraetiTe matter, &c. The Tolatile 
oil, which is obtaintHl by distilling the biuiscd fruit with water, is colourless or pale 
yellow, has an aromatic taste^ and when con centra ted, smells like the seeds, though 
more sgreeahly; in the dilute state it smells like orange-flowcra. Specific gravity 
§869 (Trommsdorff), 0871 at 14» C, (Kawalier). It dijaolves in ahokol, ether, and 
oil», both liit'd and volatile. It explodes Tiolently nith iodine. With strong nitric 
acfd, it bedi-mes very hot, and forms a rcsinona mass. Strong stdpkuric acid conTerts 
it into a broTftTi-red liquid, which carbonises quickly when heated. 

Coriander oil is a mixture of several oils, and appears to vary in composition. It 
contains a voktile oxygenated oil, and a less volatile oil containing little or no oxygen. 
The crude oil begins to boil at 160^ C, an oil then passing over corresponding in'com* 
position to the formula C^*'H"0, or C*if "0' i afterwards the temperature rise** and 
a Icfis voldtilo oil distils over, containing, according t^3 Kawalit-r, C*'lP'Of or pei'haps 
2C^H'\H0, or 4C'*fl'*.H'(J. The crude oil distilled with phosiihorio ankydrtda 
yields a distillate of camphene, C"H**. 

Coriander-oil saturated at a low temperature with ht/drochiaric ofi'd ga^, formn a 
twrmanent liquid hydrochlorate, which may he purified by washing with weak soda 
ley, and drj-ing over elilorido of calcium. According to Kawalier. it contains 
C««^*ae^, or perhaps 4(C»<'H"'.HCl) + H'O. ' coniains 



I 

I 
I 



Co; 

myrt^oiui 



r^ A ^^Tsf^lino substance said to exist in the leares of Coriaria 
(Peichier, Trommsd N, J. xri. 67.) 




CORK— CORTEPmiTANNIC ACJD. 85 

. The ontep bark of the Querctu svber, a tree which grows to the height of 30 
OP 40 feet, in the South of Europe, in the North of Africa, and in the Eaat It is dis- 
tinguished by peculiar toughness, softness, and elacticity, which render it indispensable 
for a Tariety of purposes. 

Co^ consists for the most part of a modified form of cellulose, called suberin^ which 
remains behind after the cork has been exhausts with alcohol, ether, water, and sul- 
l^uric acid. 

CheTreul also found in cork a fragrant substance, cerin (i 830), which passed oyer 
on distilling the cork with water, a soft resin, a yellow and a red colouring matter, 
querritannic acid, gallic acid, and a brown nitrogenous substance, together with 07 
per cent, calcium, salts of vegetable adds, and 4 per cent water, whidi is given off at 
100° a 

Cork oxidised with nitric acid yields oxalic, suberic, and eerie acids (i 830). 
See Asbestos (i. 415). 



A compact hornblende rock, of smooth fracture, extremely tough, 
and sonorous when struck. 



Native chloro-carbonate of lead, 2PbCLPb*C0'; also 
called cerusine. (See Lsad, Ciilobidb of.) 

COSVZV, or COBSrZO AOZB. A crystallised bitter substance, obtained from 
the root of C&mtis fiorida^ by exhausting the root with water, mixing the solution 
with moist hydrate of lead, evaporating the filtrate to an extract^ treating the residue 
with absolute alcohol, mixing the turbid solution with ether, digesting the filtrate with 
carbonate of lead, filtering again, distilling off the greater portion of the liquid, and 
leaving the remaining turbid liquid to evaporate. Comin is then deposited after 12 
hours, in stellate grou|» of delicate crystals having a satiny lustre. 

Comin dissolves easily in water and in alcohol, sparingly in ether. The solutions are 
not precipitated by alkalis, tincture of galls, iron-salts, barium-salts, or neutral lead- 
salta, but give precipitates with basic acetate of lead, and nitrate of silver. Comin 
does not exhibit basic properties ; it is partly separated from its solutions by charcoal, 
either vegetable or animal, so that these substances cannot be used to decolorise the 
•olationa. (Geiger, Ann. Ch. Phami. xiv. 206.) 



A name sometimes applied to the compact felspar which constitutes 
the base of porphyry. 



rovZV. A resin obtained from the bark of an East Indian tree, called 
Ccroa or Camova, It is brownish-yellow, of oily consistence, inodorous, has a rough 
irritating taste, and acid reaction. It dissolves easily in absolute alcohol and in ether, 
bat not moils. (Trommsdorff, Trommsd. N. J. xxi. 2, 116). 



A fine-grained modification of gneiss, occurring in Cornwall 
and in the Erzgebirg. It is of a dingy, greenish, yellowish, or reddish-grey colour, 
striated and spotted. The stratification is indistinct, and recognisable only by the 
layers of mica, or by the variations of colour and fineness of grain. (Kopp, Handw. 
d. Chem, ii [3] 212.) 



The following species of this genus of plants have been chemically 
examined. They do not appear to contain any alkaloids. 

Comus Jlorida. — The bark of this tree, which is used in North America as a febri- 
ftige, contains a bitter crystalline substance, comin, — a tannin which turns iron- 
salts blue,— an indifferent crystalline resinous body,— gum, — a small quantity of 
starch, — a colouring matter containing iron and manganese, and lime and magnesia 
in combination with oxalic acid, and perhaps also with malic and phosphoric acids. 
The fruit is scarlet-coloured and very bitter. 

Camus mascula, —The unripe fruits contain a large quantity of tannin ; the riper 
fruits are sweet. 

Cvmus §anguinea {Doa-wood),— The fruits, which are very bitter, yield oil when 
pmsed. (RochletUr*s Phytochemie, p. 115). 



An arsenate of copper from Comwall, containing, accord- 
ing to Lcroh, 30-21 per cent A»K)», 216 PK>*, 64-61 Cu«0, and 13-02 water, therefore 
6CuK).As«0* + 6H«0, or Cu»AsO*.Cu«0 -». \W0. Amorphous. Dark green. Spe- 
cific gravity « 4*166. Hardness ~ 4-5 (Handw. d. Chem. ii. [3] 212). 

COSmiFZVXTArazc AOm. An acid obtained, together with several 
other substances, from the bark of the Scotch fir {Pinus sylvestris). Dried in vacuo, 
it forms a red powder containing C'^WOf + ZUO. Its aqueous solution formB 



86 



CORTICm — CORUNDUM. 



a d(*ep gre^n colour with eeBqtiicliloride of iron. (Kawalief, Adjl du Pharm. 
butxviiL 360.) 

OORf ZCHf. An fttnorplious yellowish BabBtance c gci et in g ia tlie bark of tbe 
flspen (Popuitis irtmula), aad perhaps also in other barltB. It ii tastelesa and inodoroas, 
tparingly soluble in water, casilj in alcohol and in acetic acid, and is precipitated from 
the latt«r solution by water or flnlphurie acid- (Braconnot^ Ann. Ch. FhjB, [2] 
xHt, 296.) 

CO&trVDS^^ZTS. Sec MlBQA^nniL 

C0SUVll09B2&zm. A hydra t4?d nilicate of alumimum and iron, ibnnd with 
cunuidam in Htelkte gronpfi at Asbville, Bnncomhe Connty, North CaroHiuu The 
eiTBtallme form is j^aid to be monoclinic. An analysiB (mado with only 0*146 grm. 
of material) ga^^ 3475 per cent. SiO", 3r26 Fe'O, 8 55 Al'CF, 6'47 water, and about 
2 per e*nl. aUcali, (C D* Sbepard, Sill Am. J. [2] xii 201.) 

CORinniirMC Sapphin, Jiul/i^, Oriental AmHh^sU Oriental Topas, AdmnrniUne 
^pxir, Koitn/, (Ktrrufid, Smiri^d, Bcmantspath^ Sa/amstein, Tclhif, Corindon^ Mutk 
rfOrirwY).— Native anhydrous alumina, A1*0". CrystalliseK in the hexagonal ayatom, 
isomorphoua with the seequioxidei of iron and chrominm. Primary form an acute 
rhomhohedron IL Numerous combi nations occur, among which may be Mentioned 
E . oR, {fiff^. 146. 147) and c»P2 . oR , K . iP2 {fy. 148). 



Fig. 140. 



Ftff, 147. 



Fiff. 148» 




f 


K 


^ 


h 


m 


)n 


-■■.• 

I 


L 


\s. 


L. 


-uv^?; 



For the primliy Ibim K, the ral lo of the vertical lo tlie horizont^ axia is as 
1*3617 : 1. An^a of tlio terminal edgM - 86^ 6'. For 5P2 the angle of the terminal 
edgea — 128^ 3', and of the lateral edges = 122^ 18', CleaTEige im|Terfcct^ imrallel to 
R and oB; where it appears perfect, it is probable that fombination-facea of different 
indiriduala are present. Twin crystals also oceiir united by the fuicee K or oR {Koff^s 
Kr^fialloffraphir, p. 21 1 ). Corundum oeeura also mosaivo, granukr, or impalpable, dlia 
in"layers, from composition pai-allcl to K. 

Bpacific gravity = 3 9 to 4. Hardness ^ 9-0. Coloiir, nearly white, grc^', blue 
(sapphine), red (ruby), Tiolet yellow, and brown. Lustra Titreous, sometimes pearly 
on the basal planes oR. Transparent in rarions degrees down to mere tnvnslucenc© 
on the ddgaa. Borne crystals exhibit a bright opalescent six*sided star when viewed 
3D the direction of the vertical axis ^asieriaj. Fracture conchoidol, uneven, or 8plinterj% 
Brittle. 

Corundum is infnsible and unalterable before the blowjiipa. The powder moistened 
with eobalt-solntion and ignited exhibits a fine blue colour* With liorax it slowly 
forma a clear glass; doea not melt with soda. Insoluble in acids, but, by fusion with 
acid sulphate of potassium, it ^elds a mass easily soluble in water. 

PuTO corundum conaiits entirely of alnmina, but it is often mixed with ferric oxide^ 
titanic add, and other substances, which affect its colour and tmnsparency. Preeiau* 
corundum mdndeB the transparent varieties of pure and brilliant colour, which are 
cut for gems ; the blue variety is sapphire, the red, rubyt the yeUow Oriental 
t op aa, the violet Oriental amethyst. Common corundum indndea the opaqua 
varieties of less pure colouTp via. adamantine spar, which is crystaliised and yidda 
A very hard tjowder^ naed for polishing diamonds and otlier gems, and en* cry, which 
has a crystallo-granular structare, and is used in like manner for polishing met^LK 
gtaas, &c. 

The following are analyses of corundum by J. L. Smith (Sill. Am. J. [2] x, 354; 
xi 53; Dana, iL 112). Mag. atands for mu/fnetic oxide t»firon. 









( 


DORXDALINE. 








8' 






Hard- 
nets. 


Spec, 
grav. 


AHO>. 


M«8. 


CftSO. 


SIO«. 


Water. 




Si^bire (Indian) 
Baby (Indian) 
Comndiim of Asia Minor 


100 
00 


406 

• • 


97-61 
97-32 


1-89 
109 


• • 


0-80 
1-21 


• • 

• • 


-> 100-20 
- 99-62 


77 


8-88 


92-89 


1-67 


i-12 


2-06 


1*60 


-» 99-83 


M 


t^iearia 


65 


8-92 


87-62 


7-60 


0-82 


2-01 


0-68 


-a 99-58 


M ' 


Aaia . 


60 


8-60 


86-62 


8-21 


0*70 


8-86 


1*16 


B 101-94 


M 


India 


58 


8-89 


9312 


0-91 


1-02 


0-96 


2*86 


- 98-87 


tt 


H • 


55 


8-91 


84-66 


7-06 


1-20 


4-00 


8-10 


-> 99*92 


Emtry . 
KiOali 






57 


4*28 


63-60 


FeH)« 
88*26 


0-92 


1-61 


1-90 


-> 101*18 


Samoa 






5Q 


8-98 


70-10 


22*21 


0-62 


4-00 


210 


-> 9908 


Nicaria 






56 


3-76 


7106 


20-82 


1-40 


4*12 


2-63 


- 99-48 


Knlah 






53 


402 


63-00 


80-12 


0-60 


2-36 


3-36 


-> 98-34 


Gnmueh 






47 


8-82 


77-82 


8-62 


1-80 


813 


311 


- 99*48 


Naxos 






46 


8-76 


68-63 


2410 


0-86 


8-10 


4-72 


« 101*31 


Kicaria 






46 


3-74 


7612 


1306 


0-72 


6-88 


810 


- 98-83 


GKunuch 






42 


4-31 


60-10 


33-20 


0-48 


1-80 


6-62 


» 101-20 


Kulah 






40 


3-89 


61-06 


2716 


1-30 


9-63 


200 


»101-13 



Comndnm ocenn aasodated with aystalline rocks. The sapphire, raby, and other 
forms of predoTis oorondam, are obtained chiefly from India, China, and Cfeylon. Sap- 
phire has been found also at Newton, New Jersey, and a fine mby in Cherokee County, 
Georgia (U. S.). Adamantine spar is obtained from China and from the Ural ; emery 
from the island of Kaxos, from Smyrna, from Schwarzenber;^ in Saxony, from the 
Ural, Spain, Qreece, and other places. A boulder of blue massiTe corundum has been 
found in Buncombe Counter, North Carolina. Corundums ^re also found in numerous 
other localities imbedded in granite, gneiss, syenite, mica-slate, dolomite, basalt, and 
other rocks, but seldom large or fine enough to be fit for gems. 

Corundum sometimes absorbs water and changes to diaspore. It is also replaced by 
siUca, forming quarts peeudomozphs. 

COB'raA&m. An alkaloid existing in the roots of Corydalis bulbosd, C.fabacea^ 
and Arisiolockia cava. It was disooTered by WackenroderTKastn. Arch. [1826] Bd. 
Tiii), and afterwards examined by Peschier (Trommsd. N. J. xiii 80), Winckler 
(Pharm. Centr. 1832, p. 38), Ruickholdt (Ann. Ch.Pharm. Ixiv. 369), andMiiller 
(Vierte^jahrschrift pr. Pharm. viii 626). 

Preparation. — 1. From Corydalia btUbosa, The juice expressed from the fresh root 
is coagulated by heat, precipitated with neutral acetate of lead, and filtered ; the lead 
is separated by sulphuric acid ; and the corydaline is precipitated from the filtrate by 
ammonia, then dried and dissolved in 12 to 16 pts. of alcohol of 80 per cent ; and tho 
solution, after being digested with blood-charcoal, is filtered and evaporated to the 
oystallisin^ point By mixing the alcoholic solution with a large quantity of water, 
tlie coiydahne ma^ be precipitated in the pulverulent form (Winckler). Milller ex- 
hausts the root with water containing hydrochloric acid ; precipitates tne filtrate with 
carbonate of sodium ; redissolves the precipitate in hydrochloric acid ; again precipitates 
with carbonate of sodium ; exhausts the washed and dried precipitate with pure oil of 
turpentine ,- and agitates the oil with water containing hydrochloric acid. The cory- 
daline then dissolves in the acid and may be precipitated by potash. 

2. From the root of Aristolochia cava. The root is exhausted with water containing 
hydrochloric acid ,- the solution is precipitated by carbonate of sodium ; the precipitate 
treated wi^ alcohol; and title solution left to crystallise by evaporation. This is the 
easiest mode of ureparation. (Ruickholdt) 

Properties, — Corydaline forms light, non-coherent, greyish-white masses, which stain 
strongly. According toMiiller, itisa loose white powder. It is usually said to be 
tasteless and inodorous, but according toMuUeritis bitter when moist It is insolu- 
ble in water, but easily soluble in strong alcohol and ether. From a hot saturated 
alcoholic solution, it crystallises in shining rhombic prisms ; by spontaneous evapora- 
tion in scales. Corydaline melts at 100° C. (at 60<'--70*', according to Miiller) ; when 
strongly heated, it turns brown and gives off water and ammonia. Nitric acid colours 
it deep red, the colour being perceptible even in very dilute solutions. Sulphuric acid 
dissolves it with deep yellowish-red colour. 

Corydaline gii«s by analysis: 



c 


H 


N 


O 


62-4 . 


. 6-8 . 


. 4-3 . 


. 26-6 - 100(I)6bereiner). 
. 80-9 - 100 (Ruickholdt). 


60-2 . 


. 6-9 . 


. 3-0 . 



Hflooe hasft ben deduced the empirical formultt C^BUNO^* (Ddbereiner); 



68 



COBYDALIS BULBOSA— COTABKIC ACID. 



C^S*^*C^ (Buieklioldt); XUler, 
€7»i^S(^, Hone of Hmm CansBlK ei 
tib« acAljaet vere Bade witL purv 
I vitli acada^lk 

» (aeeovdiK to M mliei; 

■npndp&tod IrfidM- 
iMt th« pMopitate f^iitiohnBi ia 



!□■ ow 



ittboeiiM procT <faat 



■ \ffmmmgmMA; akofexj 



(fimickiioldt).' Tb» 1 1 iililii pro 



lMper«ieaLH€l,aad 

witCTp iDdii tiicTClbrc periaapB C^S^NC^JtBO * HBO 

~ irS vm «nit. vaier ai lOO" O. aDi 1^ twr 



aUmde. 



fifdvDdilanto of ecHTdiliae fiiaai a visiie InlkTmce^itate witk 

Jetimti rf dorpfaiiK/ i> tmmij pahbtft and eryrtiillitabl^ ; m> Ukewke is Ute 



mifkttU; with exoesi of nlpbniie add, a gsiiimj add nit ta olateiiiedlxi 

COKTHA^XS BtrXiSOBA. In tlie rootof tlus pUot, €OTj^a^am was fiiat Ibsnd 
Inr WiackleTp afU'nr&rds famaiie acid bj Wicke (Aim. CiL fliam. Ixzxto, 2S€). 
MttUer (Victtfdjahr, pr, FltaziiL riiL i36), iHia liaa fTaiiiiiifld tha root more 
auBUteij, fiada no imamne sad. Bf diatiUiBg tiia loot wilb vater, lie obtaiiied a 
valadle oil and aeetk acid ; eUier extradad horn 1^ dried loot f^t pla, oooaiatii^ of 
fiolowriaf auitfcr^fixedoQ, nauvaDdaaiaUq[iiaaA]lf ofeoi^^ aleoliol c£b«eted 

24*6 pla. (eoiydaliike, renn, diti^ mali^ aeetic^ fauic aid aaoefaarie adda) ; vatcr 
aolraetcd t'4 pta. (aHigmia. ataiciw and a anudl ^vaatatr of rakde add); aaud bjditK 
ehlone add* 15*6 pta. (peetia and oxalate of ealoam), toe rcddaa, aa o nntin g to 34-3 
pta., OMinated of a voodj fibre aadotlier inaolul^e mattcfs. Tbe dried root yielded &'9 
per mil. aab, eootatiiiiig in 100 pu. ^-2 pta^ EK», 104 Ka^, 6 3 Ca*0. 75 KgK), 38 
Ai*0«, 4 1 Fe*0-7oTj£*0, »6*7 SiO*. 11 3 S0», 9*1 PV, M 00». and 2-3 Ct 

eommaxmm, AnanwapcdiedbyMartintoaaoi^SuiiebaiCvwiiidilieaDppoieato 
axial in koaaao, the oelebn.t«^ Abjaainian remedj for fape-voniL Mart iaa» howerer 
(Doduier^a N, BeperL [2]. iii 177), waa not able to find iL 

CKtTAMWAMaiG ACXS* C"H*^0«, ia formed hj the aetion of aqaaooa brdzo- 
cMoriiv hydnodu^ or aulphniic add on eotanziiie, at a tempcntnre of IW* or 160° CL 

ci5H»'N0* + H*o + Ha ^ om^so* + CHKa. 

Cotaraaak «cid. 



LDceaapaitie add, GOitarEuimic add oombinea with etionginiiM^ The only &mi' 

pound of it which haa ae jet been obtained pure ia the Jftfredyiofvl^. C^H^'NO.ECL 
Thia bodj oyatalliaeB in amall, pale yellow tnfta of aillcy ne<sdl<?< ; it is but sli^tljr 
aolable in oold water, Yerj aolsble in not water; it is leas aolnble in alcohol and in- 
aolable in ether. When the pore oafrnpocind iadiaaolTed in hot water, a poTtion always de- 
oompOMes, caiuda^ an orange prodpitate (of ootamamic add) to separate ; the fame pre^ 
dpitate ia pvodnoed on cantioualj adding ammonia or potash to the aolntion ; the hjdro- 
eiiiorate diaM^lrea without alteration in water containing a little free hjdrodilonc acid. 
An aqneooa aolntion eniosed to the air pradnallif aoq[mi«s a beanti^ green colour. 
Nitric add, added drop ij drop to a aolntion of thia compound in hot water, can«» it 
to appear deep opaque erimeon bj lefiected lights and orange^jellcrw by tranamitted 
lighL Eyaporated on a water-bath with solphnrie add, it acquires a fine crunaoo 
colour when neaH/ diy; thia eolonr la destroyed bj addition of water, bat reappeart 
wlifTO tha water ia agdn eraporated (Hatthiessen and Poster, pr^o^ communu 
etUwn.) O, C. F. 



OOiTAMMWG ACtUt C^*H*K>*. — ^This subfltance is produced bj the action of dilute 
nitru; actd ou cotamine at a gentle heat (Matthies sen and Foster, Proc Roj, Soc 
xi. 6fli but the conditions necefaarjr for its certain production are not jeit knowa. 
Methylamine ia formed at the aame tinae : 

C"H'"NO» + NHO* + 2H»0 ^ C"H^W + 'S{CIl'Jf)OK 

CoUraioc, CoUrnic acid. KkttAte of 

ItdlMOlTeg easily in water, giving a solution which reacts stronglj add with litmus. 
A ie o hol disaolrca it but sparinglj^ and ethor pnx'ipitates it from ita alooholic solution. 
It gfirea white prodpitatea with acetate of Uad and nitrate of ail i^. The sUmr^mtt is 
alightly more soluble in hot water tluin in cold; it contains C"H'«A|rO*, 

Cotamine may be regarded as the mctliylutcd imid4' corresponding to «>tarnic 
add Ctjtitrnic add, ootAmamic acid, und cot^rniDe then bear to each other the i 
felationa aa malic add^ aspartic add, and mulonile or phcnylmalimide: 




COTARNINE. 89 

Cotarnicacid . C»ff*0» Malic acid. . C*H«0» 

Cotarnamicacid . C"H»»NO< Aspartic acid . C^H'NO* 

Cotamine . . C"H"(CH»)NO« Malanile . . C*H*(C«H»)NO» 

O. C. F. 

COTASWXVB, e^»«NO« + HK), or €P*H^*NO» + 2H0,—K non-volatile organic 
base, obtained by the action of oxidising agents on narcotine. It was first obtained 
bj Wohler, in 1844 (Ann. Ch. Pharm. 1. 19), as a product of the oxidation of narco- 
tine by peroxide of manganese and sulphuric acid; and, almost simultaneously, Blyth 
(Ukd. 1 37 ; Mem. and Proc. Chem. Soc. ii 168) observed its formation by the action 
of dichloride of platinum on narcotine. Cotamine has been further studied particu- 
larly by Anderson (Ed.PhiL Trans, xx. [3] 369 ; Chem. Soc. Qu. J. v. 266; Ann. 
Ch. Pharm. Ixxxvi. 196), and by Matthiessen and Foster (Ppoc. Eoy. Soc. xi. 
6^; Ann. Ch. Pharm. Supplement B. i 330 ; Bullet de la Socidt^ Chim. 1861, 22). 

Formation and preparation, — 1. Narcotine is dissolved in a considerable excess of 
dilute sulphuric acid (3 pts. sulphuric acid, 30 pts. water, and 2 pts. narcotine, are 
good proportions: Mattniessen and 'FosteTy private communication), the solution 
heatea to boiling, finely powdered peroxide of manganese (3 pts. Matth. and Fost.) 
added, and the liquid filtered as hot as possible. (Wohler directs to boil the mixture 
with excess of peroxide of manganese and acid as long as gas is evolved ; Matthiessen 
and Foster recommend to add the peroxide of manganese in the proportion given above, 
as quickly as possible, to the already boiling solution of narcotine, and to filter im- 
me<^tely). The filtrate deposits opianic add on cooling, and the mother- liquor poured 
off from the crystals contains sulphate of cotarnine and sulphate of manganese. The 
manganese is precipitated with carbonate of sodium, the precipitate filtered off, and 
the filtrate evaporated so as to cause the greater part of the sulphate of sodium con- 
tained in it to crystallise out ; the addition of potash to the concentrated solution of 
sulphate of cotimine then produces a brown granular precipitate of impure cotamine^ 
which is purified by solution in hydrochloric acid, treatment with animal charcoal, 
and reprecipitation by potash. Or, chloride of mercury or dichloride of platinum is 
added to the solution fi^ed from manganese, whereby a precipitate of chloromercurate 
or chloroplatinate is obtained, which is washed, suspended in hot water, and de- 
composed with sulphydric acid; the filtrate is then mixed with excess of baryta- 
water and evaporated to dryness, and the cotamine is dissolved out of the residue by 
alcohol (Wohler.) 

2. Narcotine is boiled with an excess of dichloride of platinum and dilute hydro- 
chloric acid. Bed prismatic orstals of chloropjatinate of cotamine are thus obtained.' 
(Blyth.) 

3. Anderson recommends, for the preparation of cotamine, to act upon narcotine 
with dilute nitric acid (1 pt narcotine, 3 pts. nitric acid of specific gravity 1*4, and 8 
pts. water) at 49° C. The liquid separated from the teropiammone {q. v.) which is thus 
formed, gives a crystalline precipitate of cotamine on the addition of potash. 

4. Narcotine treated as in the first method, acid chromate of potassium being how- 
ever used in place of peroxide of manganese, yields cotamine in a state of great purity. 
(Matthiessen and Foster.) 

The formation of cotamine from narcotine takes place according to the equation : 

C«ff^O» + - C"H»«NO« + C»«H'K)» 
NarcoCina CoUrnine. Opianic acid. 

(Matthiessen and Foster.) 

Properties, — Cotamine forms small, colourless, needle-shaped crystals, g7X)uped in 
stars. It is only slightly soluble in cold water, but somewhat more so in boiling 
water ; alcohol dissolves it^ forming a brownish solution, from which it cannot be ob- 
tained* orstallised ; it dissolves easier in ether and in ammonia ; it is almost insoluble in 
caustic potash. It melts at 100^ C, and loses 1 at. of water of crystallisation ; at a 
higher temperature it is charred, and produces a disagreeable smelL Cotamine has 
a bitter taste and faintly alkaline reaction. 

dystallised cotamine contains : 





CaUulated. 


Blyth. 


Matth. 


and Foster. 


c» . 


. . 144 . . 60-76 . 


. 61-41 . 


. 60-84 


. . 60-56 


H"» . 


. 16 . . 6-33 . 


. 6-38 . 


. 6-53 


. . 6-60 


K , 


. . 14 . . 6-91 . 


. 6-62 . 


. 6-82 


. . 6-91 


O* . 


. . 64 . . 2700 
237 . .100-00 









90 



COTAENINR 



CotarDine dned at 100"^ contaua : 



CakutaUd. 



H" . 

N . 

Water of crvstAllisation : 






144 
13 

14 
48 
219 



6575 
6-94 
639 

21-92 
lOUUO 



CaJcuiaied. 
219 . . 92'4I 
18 . . 7-69 
237 . ♦ 10000 



Blyth. 

6595 

639 



7-61 * . 7^22 



The formula originally proposed for cotamke bj Wohlen "^^ C^*S^*NO^ ; Blyth 
gaveitflfonniilttas C"^i/'"M>*; Gerhardt (Prick de Chmde Orgimiqutj, 1845, ii. 298) 
adopted the expression C"U"NO'(- C^^J*aVO*); Wertheim (Wien. Acad. Bcr. tI 
111), believing in tlie eiistenc^s of seTeral homologoua varittiea of cotaminEj, ga\^o the 
formulii C ' *H^*NO ' ( = C^^*H* WO" ) for what he called methyl-cota mine; M a t th i e s a e n 
and Foster regard cotaroino as always of thesiime comf>osltion, and ropresexit it by the 

formula C'='H'*NO" ^^^*^?^*^ {n, that is, as meth^l-cotamimide, (See Cotarkic 

AciiJ.) .... 

The aqueous solutiou of cotomiiie precipitates feTroua and cnpnc salts ; it give* 
no coloration Trith ferric salts (Bly th). It ie also precipitated by tanniiL (Wohler.) 

Dtcmnpontims.— 1. If Uric acid dieeolvea cotamine witli red colour, and, if heatod, 
OMdises it» fonning oialic acid, and afterwards awpbylljc acid, (y, v.) (Wohler, 
Anderson^ Matthiessen and Foster.) Very a i lute nitric aciii, gently heated 
with cotaxnine eoraetinics produces cotamic acid, C*'H'=0*, and methylainine ; 

C'*H'"KO« + 2H'^0 ^ C'^H''0» + KCH* 

CoLinitne^ CotAnifc acid. Methjlitmltie* 

(MatthicflsGO and Fofltar.) 

2. Heated with fiydrocMortc, hifdriodic, or dilute sulphuric acid to 149° C, in a 
scaled tuW, It yiolds chloride or iodide^of mctliyl, or methyl-sulphuric acid, asid cotar* 
iiamic acid, C"*H"NO< (p. 88). 

c'*H^"NO* 4- WO + na - c"H*«no* + ch"ci 

Cuiarqiae, CoCunaiale acid. ChJoride of 

miriiiyl. 
(Matthiessen and Foster.) 

3. With iodidt of ethyl at lOO*^ C. it yields hydriodate of cotamine, but no otbylised 
derivative. (How, Ed, Phil, Trans. toL iii. ; Ann. Cli. Phaira* xcii) 

SixTS OF OoTABsTjTB. The Balta of cotamine are for the most part very soluble ; 
they are obtained dir*?ctly, by solution of tlie base in dilute acids. 

M^drocMeraie of Cotanmif, C'*Hi»NOlIICl ( + 2|1I'0 ?), is obtained by evaporat- 
ing lbs aqueous solution, in the form of long silky crystula, which are \<:Ty solnl>li' in 
imter. It loaea 14'88 percent, of water at 100'= (Blyth): tho above formnJa cor- 
n^ponda to 14*97 per cent Dried at 100^ C. it containg, according to Blyth's analysis, 
fl7'3& |)er cent carbon and 573 hydrogen; the formula C'=K"N0',HC1 requiree 66-36 
pt^r cent C, and 6*48 H. 

€M4}roplntt7jaff' of Coiarmnr, C''H^*NO^HCl,PtCl'.— This salt forms, when precipi- 
tated in tho cold, a lemon-yellow, crystalline precipitate, reBcnibling chloropfatinate 
of ujnmonium; when hot aolntiona of hydrochlorate of cotiimiue and dichloride of 
j>latiniim are mixed together, tJie double salt separates as the mixture cook, in smallt 
round, transparent nodules, of a reddiflh*yellow colour (Wohler). It is obtained in 
the form of large, dark-red, siX'-sided priems, by boiling a solution of narcotine in 
hydrtx hlodc acid with an excess of dichloride of platinum (Blyth). This salt is very 
pilightly soluble in cold wat4?r, but somewhat mors so in hotwatej; it appars, however, 
to l>e altered by repeated solution in hot water. It can be boiled with ammonia 
withnut Qnd(»iTgoin^ decomposition. Boiled with baryta-wat«r, it is decomposed, and 
metallic jilutinum ia precipitated. 
It contains \ 











COTTON. 








Cmlemlated, 


W6h1er. 
34-9 34-2 


BI7U1 
34-4 


360 


Matth.andF<MC0r. 


C'« 


144 


38-84 


^ 


H" 


14 


3*29 


3-2 


3-6 


3-3 


3-6 




N 


14 


3-29 


4-4 










0« 


48 


11-28 












Pt 


99 


23-27 


23-0 


22-6 


22-9 


23-0 


23*3 23-1 21 


Cl« 


106-6 


2603 


24-1 












'426-6 


100-00 





91 



Bljth dried the salt for analyms at 100^; ICatthiessen and Foster at the Ofdinair 
temperature, orer snlphnrio add in vacuo; they could not obtain constant resfolts with 
the salt dried at lOO*'. 

It sometimes happens that the treatment of narcotine with dichloride of platxnnm 
gives rise to another chloro^tinate, which dystallises in long, bright, orange-yellow 
needles. This salt, which Slyth supposed to contain a peculiar alkaloid, which he 
named narcofftnin^ C^B^NC^\ is decomposed when boiled with ammonia, into nar- 
cotine and cotamine, and is probably a double chloroplatinate of these two bases. 
B]yth*s analytical results acoora nearly with those required by the formula 

C«^»«NO«.HCLPtCl«> 
CaH"NO».HaPtCl»f 

CUorauraU of Cotamine has a beautiful dark red colour. 

CUoromerewraU of Cotamine, C**Hi'N0*.HCL2Hg01, forms a pale yellow pKcipi- 
tate, which gradually becomes aystalline. It is not precipitated from rather dilute 
wann solutions, but is deposited on coolinff, in small pale yellow prisms. It appears 



to suffer decomposition by repeated ciystaUisation. It contains : 

Calemtated. W6hler. 

Nitrogen . • . . 14 2*66 2*6 

Mercury .... 200 37*98 37*96 

Chlorine .... 106*6 20*23 20*68 G. C. F. 

OOVrOV. The filamentous matter attached to the seeds of Tarions species of 
Goi^fpium, a genus of plants belonging to the Malvaceous order. It consists of 
hairs sprin^g from the surface of the seed-coat, and filling up the cayity of the 
seed-xessel in which the seeds lie. These hairs are long weak tul^ which, when im- 
mersed in water and examined under the microscope by transmitted light, look like 
flat, narrow, transparent ribands, entirely distinct from each other, and with a 
perfectly eren surface and uniform breadth, rarely jointed, and if so, having the 
Mrticulations perpendicular to the length of the tube. The individual tubes are very 
weak and frajiple, and it is only when many are twisted to«rether, that they acquire 
any appreciable degree of strength. Linen, on the other han^ consists of woody tissue, 
in the shape of long thick-sided tubes, adhering in bundles, the articulations being 
always oblique, and the ends of the tubes pointed and overlying each other; moreover, 
the individual tubes are much stronger than those of cotton. In short, cotton is a 
development of the parenchymatous tissue, which is the weakest among the elementaiy 
oi*gans of a plant; unen, of the woodj tissue, which is the strongest: hence the well- 
known superiority of linen to cotton in strength. 

Cotton fibre consists of nearly pure cellulose associated with only 1 to 1| per cent 
of inoiganic matter. Hie following table exhibits the composition of cotton (aftor 
deduction of the ash), as compared with that of pure cellulose C*H**0*. 







Analyses of Cotton. 








^».„-nmL » ochinldt PettcQ- 
""•^•' and Hecker, kofer. 


Calculatioa. 


osjp 


. 44-37 
. 7-24 
. 48-39 


44-20 43-27 44*6 
7-04 6*30 61 
48*76 60*43 49*4 


C* . . 44-44 
H'« . . 6-17 
0» . . 49*39 




100*00 


100*00 100-00 100*00 


100*00 



Cotton (and linen) may be distinguished firom silk and wool by their behaviour 
with sulphuric and with nitric acids. Silk and wool are turned yellow by immersion 
in strong nitric acid, whereas cotton and linen remain colourless. When woollen tissues 
containing eotton or linen are i^^ersed for a quarter of an hour in sulphuric add, the 
cotton and. linen first swell to a pasty mass, and afterwards dissolve, while tiie animal 
fibres remain unaltered. (Bottger, J. pr. Chem. Ixxiii 498.) 

Cotton diasolves in sulpiuHe acid more quickly than linen ; hence it may be detected 



92 



COTTON. 



m linen hj the following method. The tisstie^ after being T©p*atedl^ wiahed wit!i 
rain*Tnit<"r, boiled with wateri and dried^ ia dipped for J to 2 minates ui oil of vitriol, 
then ciirofully pressed under w&toT with the fingers, washed with water, immera<>d for 
u few seoondi m uqaeona ammoma, carbonate of potaasiam^ or carbonnt* of &>dium, 
QgMm washed with water, aod dried between filtering paper. By this treatment, tho 
cotton fibres are diasolTed, while the linen fibres aro merely rendered thinner and 
more tmnslueent, aecnording to th© duTHtion of the experiment j ivft<?r a short immersion 
the cotton fibres appear transparent, while the linen fil»reB remain white and opaque. 

Another distinction between cotton and linen is that the latter acqutrea a deep 
yellow colour by boiling with water containing ita own weight of hydrate of potassium, 
whereas cotton is little or not at all coloured by the same treatment, (Gm» xr. 140.) 

Cotton cloth (calico), imioeraed for 10 — 30 minutes in ejmpy potojtk-ley^ and then 
wasb«d with alcohol of specific grarCty 0825, contracts by^ afler drying, and contains 
1472 per cent, potaah, eorreflpondiDg to the fonnnla 4C*H'*0*.K*0 which roqtiirea 
14-o9 per cent. K*0 (Gladstone, Chero. Soc. Qn. J. v. 17). Calico immersed in 
MmJa4rtf of spet:ific pravity r342 and treated in a similar manner, shrinks in dr>^ng 
by 1, and contains 9 58 p4?r cent^ B*5da (4C*H"(.>*.Na*0 = 965 per cent,). Unwoven 
cntton forms a similar componnd ; lonj[5er immertfion or the nse of a stronger soliitioQ. 
iippears to produce partial solution and dee<imfposiilion. Cotton also unites with soda 
in other proiwrtions, but never with a larger quunlity than that coiituint'd in the com- 
pound just mentioned. Water abstrat'ts till the soda from the compounds, and leaTea 
a shrunken tiasue which takes more brilliant colours in dyeing than ordinary calico. 
(Gladstone^ he. cit. See also Mercer, Hep. Pat. Inr. 1861, p. 368; Qm. xt, HI.) 

Cotton immersed in solutions of a/am or a<c/a^tf of alufmniwn^ does not lepiirateany 
alumina ; but if the solution of acetate of aluminium, feme aectate, or any other salt 
containing a volatile acid be left to dry on the cottOD, the acid volatilLies after 
» while, and the base ia so firmly fixed on the cotton, though only mechanicallj» that 
it cannot be removed by washing with water (Walter Crum, Ann. Ch, Pharm, 
Ir. 223, Compt, rend, xlvii 961). If the cloth after this treatment be immersed in a 
coloured solution* such as that of logwood or indigo, the colouring matter forms an 
insioluble compound with the base, and thus becomes permanently fixed upon the cotton 
fibre ; whereas, if the cloth wore merely dipped in the coloured infusion without being 
iirt'i-iously treated with the metallic salt, or fnordmii^ the colour imparted to it would 
be immediately remored by immersion in water: cotton, flax, hemp, and other 
Tegetable fibres do not> like wool and silk, exert any speeific attractire power on th« 
colouring matters mixed with mordants. (See Dmsxso*) 

Culture of Cotton, — Profetsor Mallet of Alabama has lately published the com- 
mencemeiitof an elaborate inTcstigation of the chemiL-al and phyHcul conditions of tho 
cultivation of cotton (Proc Eoy. Soe* xi. 340), from which the following general con* 
du«»ions aro drawn. 

The annual cotton plant, as cultivated in America, attains ila principal growth during 
four monthsj though it continues to devclope seed and fibro for a much longer period. 

It n^uires a very finely divided soO through which its rootleta can penetrate with 
facility ; the average masa of soil interpenetrated by the roots of each pWt is about 5 
cubic feet. 

Cotton is not an exhaustive crop, inasmuch aa the great mass of the plant — root, 
stem, branches, leaves, and emptied ImsIcs — remaina upon the field and is ploughed 
into tho soil, and nothing is removed but tlie fibre and the seed : and the greater |jart 
of the latter ia ako returned to the soil, the seed being thickly strewn by handfulls in 
a continnotia row, from which tho plants arc afterwards thinned- The cotton fibro, 
which constitutes the salable product, and is absolutely cjirried oflT the land, may be 
looked upon aa a very light crop ; a bale of 400 to 600 lbs to the acre is sometimes 
obtained under favourable circumstances, but this is much above the average for 
npland cotton. The fibro pelds from 1 to 1-5 per cent, of aah^ so that at the most. 
TJ lbs. of mineral matter will be removed annually, which ia not half aa much as is 
removed by a crop of wheat of 25 bushels to the acre in the ^rain (d<mty and losa than 
^ the amount removed by an average crop of potatoea. Sometimea, however, a con* 
sideTable portion of the seed is removed from the plantation to be used for the ex- 
traction 01 oil, tlie cake which remains being exported to Europe for cattle-food. This 
practice teu<hi pnvatly to tho exlmustion of the cotton soil. 

Cotton is decidedly a §vn-piant, requiring a high summer temperature and plenty 
of sunshine. A mcderate sn|iply of min is advantageous in the early stage of growth, 
but heavy rains are injurious even in that stage, and later in the scaBon they are 
absolutely destructive, A water-soaked soil is decidedly unfuvourable, tho tap-root 
not striking down in such soil, and the plant looking small and sickly, and bearing but 
little cotton. The soil most favourable for cotton cultivation is a 'fin*'ly divided soil 
capable of abscirbinj^ a considerable quantity of aqueous vafionr from the atmoffjihere 
and retuining it in a aiaiv ^f mlhesiou or of chemical eombinulion, so as not to rendt^r 



COTDNNITE— COUMARIN. 



m 



the soil moist to the touch. Sacb a soil et)abl(?s the pXimi to withstand riciEsitndes of 
woiilhei' And seaflon^ Btoring up hygrospopi(? moisture in damp seasons,, and yieldinp a 
gradmil supply of it to the root« in the latter stago of the growth when seed and fibre 
are forming. Another essential i^onditlon of tho soil iis tho power of gradually absorb- 
ing and yielding a considerabk quantity of gases, especially ammonia, and of minenil 
matter withdrawn &om Bolution. 

All these conditions are fulfilled in a high degree by the soil of tho prairio region of 
Central Alabama, which is a stiff aluminous day, contaiining a moderate amount of 
organic matter and of the mineral substaiiced needed by the plant on food — of gnuit 
uniformity, and in an exceedingly fine state of division ; aboTe all, po8ae«aing a Very 
bigh capacity for absorbing ana retaining heat, moisture, ga.**»^, and soluble mini? ral 
xoatter. It was found to be capable of condensing 52 times its own volume of ammonia 
gas, and the suteoil, which is calcareous^ was found to absorb fil times its ovra 
Tolomo of the same gas. 

COVU Jl M 1T&> Native chloride of k»ad, PbCl+ found in the crater of Vt^suriiMi 
ait«r the eruption of 1822, in acictilai" crjstiili* of the trimetric system, and capillary 
masaeat white, having a strong luBtre, of spociflc gravity 6238, and soft enough to be 
scratch ixl by the naiL 

COOTffllMftlirgra, C»HrtfO» = N>H=*.D*H'0«— Produced by the action of 
ferrous acetata (iron filings and dilute acetic acid) on nitrocoumarin. The reaptiou 
mast be (wntinued for twenty-four houns, and the filtrate concentxnit4>d by evoi>cjration ; 
it then, on cooling, d<>posits coumarin in flue yellowieh needles, often several centi- 
metres long. It is nearly insoluble in crild water and in ether, but dissolves nmdily in 
Jb^iling water or alcohol. A saturated ftolution of ferrous acetate appears to dissolve it 
I'iHiOre readily than cold water. It melts l>ctween 168° and 17t>'^C», and if cautiously 
' ftoBcd to a higher temperature, sublimes Tv-ithout decomposition in pale yellow sctdea. 
It is rapidly decomposed by boding potash ; the liquid saturated with an acid deposita 
btxTWD flakafr 

Coumaramino unites with acids, forming soluble salts, from which ammonia preci- 
pitates the base in a crystalline meiss. The hr/drochlorate forms scales very soluble in 
water, Tho chhr&ptaiinaU, C*H*NO^.nCI.PtCl', is a yellow crystalline prccipitalo in- 
solablc in water. (Chiozza and Prapolli, Ann. Ch. Pharm. xcr* 252.) 

COiraCASXC ACXIB, Q^WO^ = C"H^O-.H.O = eoumarin + 1 at. water. (Be* 
Inlando, AniL Ch. Pby«i. [3] vi. 343.— Bleibtreu, Ann. Ch. Pharm Jix. 177.)— I'l^'- 
pared by boiling coumarin with strong potash-lfy. adding solid potash if necesiittr)'', 
and precipitating by hydn>ehloric acid. Crystallises in colourless brilliant lamina?, 
having a bitter taste, and soluble in water, alcohol^ and ether. It melts at l&O*^ C, 
aod at a higher temperature decomposes partially, yielding a crystalline sublimate, and 
learing a brown residue. By distillation it ^elds an oil, which reddfna fi^rrie salts 
and appears to unite with potash. Couraanc acid, when pure, does not Impiirt any 
violet colour to ferric salts. TVhen malted with potash it gives off hydrogen^ and 
yields salicylate and apparently also acetate of potassium : 

C»IPO» + 2KnO = C'H»KO» + C'H"KO» + H\ 
CotiifiArlc SallcyUi** of Actitate ol 

aclj, potuitum. potiiilum. 

Coomaric acid decomposes carbonates. The formula of the coutnarat^s is C'H'O^.lff. 
Coumarate of ammonium does not precipitates barium-salta. CowmaraU ^f htuf is a 
white precipitate, pulverulent, and insoluble Ln water. Coumarat^ of silver is a light 
yellow pulverulent precipitate, or if formed in presence of ammonia, onmge-coloured 
and flocenlent, 

COtnic Aj|Xir« (yE*0\ ov C^*H*CA ( G u i h o u r t, Histmr§ des DrmueM simples, 
— Bonllav and Boutron-Chaillard, X Pharm. jti. -180. — Bolalanaa, Ann. Ch. 
Phys. [3] ri.3't3,— Bleibtrcu, Ann. Ch. Pharm. lii. 177.- Gm. riiL 321.)— This sub- 
stance' exists in considerable quantity in Tonka beans, the fruit of Coumantma odorata, 
ta BipUrpx od&rata, being found in small while crj'sfala between the seed i^ating and 

tkf^meL It is also found in woodruff (Afiprrn/a odorata), in Mddoiits ojfictna^is, in 
flow<*rs of sweet-scented vernal grass (Anihoxanthum odoratum), in the leaves of 
Faham, an orchidaeemiB ploDt {Angrifctim fra^ans), in the leaves of Orchis fusca (Bley ), 
and in the dried lesTefl of Ltastris od4>ratissima, a composite plant growing in the 
■oathern parts of North America (Procter, Rep. Chim. app. 1861, p. 143). In som<s 
of tbesf plants, the coumarin was originally mistaJ^en for benzoii; acid. 

O •"'""'■'" 1% easily extracted from TonJcti beans by digesting them in strong akolioL 
On - the alcohol^ a crystalline magma of coumarin is obtained^ which m»iy 

be 1 I und frred fiim n quantity of adhering oil by meaiiH of animal charcoal. 

Cuuimirui is ei>1ourU'S8 ; it crystal! ises sometimes in small roctangular plates, soma- 




[ 



91 COUHBARIL RESIN ^ CREAM OF TARTAR. 

timefl in Ijugo prisms belonging to tho trimctric r^tom, cdP, f oo, with od^q» 
predominant Inclination of tbe fiwoa 00^^001^03 « 10 0"^ (nearlj)» 00 P : P » = 
104-d (ni>ttrly)» : 6 : «? - 0364 : 1 : l'(»3 5, It melta at ^0° C, and l>oiia at 270° with- 
otit aeaaible alt^mtioo; haa on agr^eeabio aromatic odomr^ and a btiraing t^iste; the 
vapour acts very strongly on the brain. 

Coumarin ia ne&rlj insoluble in cold water, but boiling wat«r diasolYfla it abun- 
dantly, and deposits it on cooling in ¥eiy flleoder Deedli«. It disaolvea witbottt altera^ 
lion in dilate acids. Strong stt^kuHe acid chaw it immediately. Strong nitric add 
conTerta it Into mtrocoufnarin^ and, after long boiling, into pierio add. Heated with 
exctea of poi^skf it yidda salicylic add and ooumaric a^^id, C*H'*0'. Chlorins and bro- 
mine fonn crystalline compoundi* witb eciumarin ; iodine converts it into a bromie-green 
crystalline substance. With ptnfacUoTide of antimony, coumann forms a dystallino 
oompotind containing C*H*0'.SbCl*. 

Nitrocournarin. C" H*( N0')0 '. — Obtained by prcj eeti ng conmarin by small por^ 
tions at a time into cold faming nitric acid, and precipitating with a large quantity of 
water. It is then deposit4?d as a snow-white floeetilent mass. It dissolves in boiliQg 
water, alcohol* a^nd ether, and crj-atallises from tho solution in amaO white silky 
needles. Melta at 170^ C, and sublimea undeeompofted at a high temperature in 
nocreotui crystals. Pot^^h colours it deep red and dissolve* it. Acids addrd to the 
solution throw down unaltered nitrocoumarin. It diaaolres in ammonia ; the solution 
when boiled evolves ammonia, and on cooling deposits part of the nitroooumarin in 
white crystals, not containing ammonia ^Bleibtreu). Ferrous acetate converts nitro- 
coumarin into coumaramine. (FrapoUi and Chiozaa, p. 194>) 

The ammoniacal solution of nitrocoumarin, freed from excess of ammonia by boiling, 
and filtered, forms, with oottaU of Uad^ an orange-yellow precipitate, 2CH*(N0*)0*. 
3PbX), soluble in a lai^ quantity of water, less soluble in alcohol, insoluble lq ctner, 
decomposed by acids. With nitrate of silver, in like manner, a bcautiM orange-coloured 
precipitote, C*H*(NO*)0*.Ag=0, is obtained, which cjcplodes when heated. (Bleibtren.) 

COHlLBJiJU^ KSBSir. A name sometimes given to West Indian ajiimd refiin^ 
obtuiut^d from the Ilf/nuntea CourbariL (See i. 296.) 

OOnZfiRAirXTS. A sUicato found in the neigh l>ourhood of Conseraa in the 
Pyrenees. It contains 52'37 per cent. 8t0', 2402 Ainj*, 11-86 Cit*0. 1-40 2ilg*0, 5-52 
K*0, and 3-96 Na*0 (D nf re n oy)^ which is nearly the c/>mposition of dipyre {q, v.) Ac- 
cording to Dnfrenoy, the crvstalB belong to the monoclinic system, whence he refers it 
to Labradorite ; but, according to K. P. Grey^ jun., they are di metnc, like those ot 
dipyre, which mineral is also found in the Fame locality. Specific gravity - 2 '09. 
Hardness » %% or rather abo^e. Colour bkek to grey. Lustre waxy. Opaque, 
Melts to a white enamel before the blowpipe. Insoluble in acids. (Handw. d, Ghem. 
ii. [3] 220.— Diina, ii. 206.) 

CfOVS^XiXir. Native protosulphido of Copper. See Cofpbb, Scu^ehies of (ii, 74 V 
CM^XTOiaVSM, See Cmchtonitb. 

C KAlwa B aLamzTXniA. Sea Kale.— A cruciferous phmt, the young sprouts of 
whioli contain, accohlin^f to T. J, Hcrapath (Cbem. Soc Qu- J. ii. 4)^ in the fre?»h 
state 071, in l±e dry btat^ Q'9 per cent, ash ; the leaves 1'7 per cent in tho fresh, and 
lfl"7 per cent, in the dry state. The composition of tho ash is as follows : — 

CO* 80* P'0» KH) Ntt»0 KaCl 
Soluble in WRt^ J??prouta . 4-2 21-8 fil 6 7 236 trac« 
soluble in watijr j^ea^^ ^ g.^ ^^^^ ^^^ 21 20-8 121 

Ga*CO« Mg*0« Ca'SO* Ca"PO< MgTC* phlS!;!?*., suiou 

Insoluble in water J?I"^^*%5'^ *^^ *!^^ JST ^"^' trace* 42 
(Leaves 27-2 trace l& 13*1 trace 16 01 

C&A.'VSOnr. A non-azotlscd bitter principle, obtained from the fresh tranch- 
bark of the wiiite-thoro (Crattpgus ar^at'antha). It crystallisee in greyish -white no- 
duleK, like grape-sugar, has a bitter tajste, dissolvi^ easily in water^ 1cm3 easily in 
alcohol, not at all in ether, and doea not combine either with acids or with *lW^i«, 
(Leroy, 1. Chim. M6d, xvii. 3.) 

MJMJkTimiSimm Gmelin*B name for CHKATtuniH (j. v.) 

CM^xm^rrm. See DuFBEVHrrE. 

CKX^aJiS. The fatty portion of milk, which rises to the surface when fr-esh milk 
is hft at rest for twenty- four hours, Berzelius found in 100 pta, of cream fix>m cow's 
milk, 4-5 pts. of butter, 3*6 casein, and 920 semm. 

CSBajlt OP TAKTASt* Acid tartrate of potasaimn (see Tartaeic Aero). 



CEEATINE. 95 

C*H»N»0«, or C^B*N*0^. (Chevreul, J. Pharm. xxi 234; Pet- 
tenkofer, Ann. Ch. Pharm. lii, 97; Liebig, Ann. Ch. Pharm. Ixii 282.; Heintz, 
Pogg. Ann. Ixii. 602 ; Ixz. 460 ; Ixxiii. 696 ; Izxiy. 125 ; Compt. rend. xziy. 600 ; 
Gregory, Chem. Soc. Qu. J. i 25; Dessaignes, Compt rend, xxxviii 839; xlL 
1258; Ann. Ch. Pharm. xcvii. 339; J. Pharm. [3] xxxii 41; Gm. x. 249; Gerh. 
i 530 ; iii. 939 ; ir. 893.) — An organic base discovered in 1835 by Cheyreul in the 
juice of flesh ; more minutely examined by Liebig in 1847. 

Sources. — ^In the muscular flesh of mammalia, birds, amphibia* and fishes. Lean 
horse-flesh contains 0*070, and the flesh of poultry 0*35 per cent, of creatine. That 
of the marten yields less than that of poultry, but more than that of other quadrupeds : 
after horse-flesh follow, in decreasmg series, the flesh of the fox, roe-buck, stag, 
hare, ox, sheep, pig, calf, and pike. Fat animals yield much less creatine than lean 
ones ; e, g, ^ fox fetttened on meat for 100 days, yields only -^ as much as one that 
has been killed in the chase (Liebig). Bullocks heart yields 0*142; the flesh of 
poultry 0*321 ; that of the pigeon 0083, that of cod 0*170 ; and that of the ray 
0*61 per cent ^Gregory). Human flesh yields 0*067 per cent ; that of the alligator 
likewise contains creatine (Schlossberger, Ann. Ch. Pharm. Ixvi. 80; xlix. 344). 
The flesh of the Boiqual whale {Balanopiera musctUus) likewise yields a small quan- 
tity of creatine. (D. Price, Chem. Soc Qu. J. iii 229.) 

Stadeler, has obtained creatine from the flesh of the dog, pigeon, Spinox acanthus, 
and PetroTMfzon fiuaiaiilis (J. pr. Chem. Ixxii. 256). Creatine is likewise found, toge- 
ther with creatinine, in urine ; together with creatinine and seroUne in blood (Verd eil 
and Marcet, J. Pharm. [3] xx. 89) ; and, together with urea, in the brain of pigeons 
and of dogs. (Stadeler.) 

It is not yet decided whether creatine exists, as such, in the liying animal body, or 
whether it \a formed from creatinine existing therein, by the process of preparation. 
Creatine and creatinine differ in composition only by the elements of water, and are 
easily converted one into the other, — creatine into creatinine imder the influence of 
adds, creatinine into creatine, by the action of alkalis, the action in either case being 
accelerated by heat Now, in preparing crefttine either from flesh-juice or from urine^ 
the usual process is to neutralise with an alkali, and concentrate the liquid by heat ; 
by this process the creatinine existing in the original Uquid is sure to be converted 
[»rtly, if not wholly, into creatine, and it is possible that the whole of the creatine 
actnaUy obtained may be produced in this way ; for there is no simple reaction by 
which creatine can be detected in the original liquid, in presence of creatinine. fVom 
the experiments of Dess aignes ( J. Phanu. [3] xxxii. 41), it appears that human urine 
yields more creatinine and less creatine the more qnickly the process of separation is con- 
ducted. Liebig (Ann. Ch. Pharm. cviiL 334) found that the fr«sh urine of a dog which 
had been fed on meat for some weeks, yielded, when mixed with milk of lime and 
immediately evaporated, a considerable quantity of creatinine but no creatine, but if 
left to stand for six weeks before evaporation, it yielded creatine without creatinine. 
In this case the creatine evidentiy resulted from the decomposition of the creatinine. 
Dessaignes is of opinion that the creatine of muscular flesh is likewise produced by the 
decomposition of creatinine. 

PreparatUm, 1. From musctdar flesh, — a. The aqueous extract of beef is evapo- 
rated in vacuo ; the residue exhausted with alcohol, and the alcohol evaporated till 
the creatine crystalHses out The greater portion remains, however, in tiie mother- 
liquor, being prevented from crystalHsing by the presence of foreign bodies (Chevreul). 
In a similar manner, Schlossberger obtained creatine from the flesh of the alligator 
and purified the crystals by washing with cold alcohoL 

b. The fi^h lean muscular flesh of mammalia or birds, is freed as much as possible 
from &t (which would stop up the press-bag when the meat is subjected to pressure), 
and chopped up fine ; 5 lbs. of it are then well kneaded with an equal weight of water ; 
the li<^uid is well pressed out in a coarse linen bag ; the residue twice treat^ with water 
in a similar manner; 5 lbs. of muscular flesh kneaded together with the expressed 
h<^uid ; the residue kneaded with the third expressed liquid, and then after pressure 
with 5 lbs. of pure water ; and the united liqmds are strained through a doth. The 
resulting reddish liquid, which reddens litmus, is kept at 100^ C, in a large glass 
flask over the water-bath, till the albumin and blood-red have completely separated 
in the form of a coagulum, and a sample of the licjuid remains dear when boiled. 

To decolorise the liquid obtained from some kmds of meat, it must be heated in a 
basin till it troths up. The liquid is then strained, first through linen, the coagulum 
being pressed out, then through paper.* The filtrate is then mixed with saturated 

* Th« filtrate obtaiiMd from the flesh of the ox. roebuck, hare, or fox, which contains a large qoantit/ 
of Mood, reciUaf a reddish tint ; that fVoni veal, poultry, or pike it nearly colourless ; game and poultry 
yield aaearly transparent filtrate, which is very favourableto theobtaining of creatine; horse-flesh and cod 
fitld a turtfid filtrate. If the filtrate were eraporated alone, eren below lOOP, it would become coloured 



96 



CREATINE. 



bittTTta-wator, the addition of that liquid being conttnucKl, even after the filtrate hai 
been rendered iioiilral or alkaline by it, as long as a precipitate of phosphate of barium 
and phof-phiite of ma^nttiium continnes to form ; the filtrate? I'vapomted in a. shallow 
bsisin over the wat^^r-ttath to ^i ; and tht* thickish residne act a»ide, first in a warm 
pboe to eraporate further, Mid then, after crystallisation has commenced, in the cold.* 
Tht5 n€ LI Ilea thus obtain td are acparatcd from the mother-liquor bj filtration, wa.*»hed 
first with water, tlien with alcohol, and dissolved in boiHnpj water ; and the aolution, 
if coloured, thgctfted with a small quflntitj of b^TodchEireoal, then fllter<-d and kft to 
cool, whereupon it yields pnre cryatals of creotiue (Lie big). If a suflBcient quantity 
of baryta- wattjr has not befn added, the crystals will he contaminftted with phosphate 
of magnesium. In th«t case, the hot tti^aeoua solution must be boded with a small 
quantity of hydrated oiidt* of lead; digested, after filtration, with blood-charcoal, 
which remove's the laat traces of leadj and the filtrate again left to crystalline. 
(Lie big-) 

€, The chopped flesh of pike, when boiled with wat4?T, swells ^p to a gummy mtiss, 
from which the liquid canuot bo expresaed^ A miittiiro of the chopped fleiih with 
water must therefore be thrown upon a funnel ; small quantities of water allowed to run 
gradually through; and the alightly ttirbid, acid liquid, which smeUa and tastes offish, 
separated from the soft, white coagulum, precipitated with baryta- water, then filtered 
and eraporatfid. It forms on cooling a colourless jelly, iu which, in the course of 2i 
houra^ ciyatals of creatine begin to form. (Lie big.) 

The extract of the flesh of poultry or pigeons deposits brown flakes, together with 
the creatine crystals; — the flesh of bullock's heart often yields but few of the purer 
crystals, hut a considerable quantity of brown flakes, from which boUiu^ water extract« 
a large additional qtiantity of creatine. From skate and cod the juice may bo easily 
expressed, aft«r tho flesh has been mixed with rather more than equal quantity of 
wat^T", the jeEy ultimately obtained from it, in which the creatine-eiystttls form, 
dissolTes reatlily in cold water, and deposits more crystals : the flesh of cod yields the 
whitest creatine. From the syrupy mothcr-liquors of crude creatine, chloride of zinc 
does not form any zincochloride of creatinine, or only a trace ; but the mother-liquors 
obtained in the recryBtalHsation of crude creatine yield this precipitate on addition of 
chloride of dnc. f Q rego ry.) 

d. Chopped tlesh mixed with coarsely pounded glass, is digested with 1 4 times 
its Tolume of alcohol at a gentle heat; the liquid is then pressod out and distilfe^l, the 
ri'sidue ti-eated with bai^ic acetate of lead, the excess of les.d separated by salphydric 
acid, and the cleur liquid eTaporated to a syrup. On cooling, creatine crystallises out ; 
and aEer some days tht* crystallino msss is spread out on unsizwl paper to absorb the 
mother-liquor; after which the creatine is dissolved in hot water or alcohol, and ro- 
erystallised* (Stiideler, J. pr, Chem. Ixxii. 266.) 

2. From Zinco-chloride of CnGthiinr. — a. The solution of this compound in boiling 
water is dige*ited with hydrated oxide of lead, till it acquires a strong alkaline reaction ; 
filtered frpm the oxide of zinc and oxychloride of lead ; digested with a little bhjod- 
charcoal, which removes the small remaining quantity of lead, together with fibrlii ; 
the filtrate evaporated to dr^'nesa; and the remaining mixture of creatine and creati- 
nine, treated with an eightfold quantity of Ixiiling alcohol to dissolve out the latter: 
the alcohol, on cooling, likewise deposits crystals of creatine, wMdi are added to the 
luidlissolved residue of creatine, and the whole is pnrlfied by recTystallisatlon. (The 
alci^hol filtered after cooling deposits creatinine: Liebig.) — h. Tbe boiling aqueous 
solution of the Kinc-compoun<l is treated with baryta-water, which precipitates dnc- 
oxide, together with the greater part of tlie adbei-ing fibrin ; cjirlmnic acid pas is 
pai*ed through the filtrate ; the liquid again filtered to separate carbonate of barium ; 
the filtrate evaporated to drj-ness in vacuo ; tiie residue exhausted with alcohol ; the 
baryta which has been taken up by the edcohol aa chloride of barium, prcxii pita tod by 
sulphuric acid; the liquid iigain tlltered, boiled with oxide of lead, treated with 
ab^Iute alcohol to precipitate all the chloride of leari, and filtered fiYtm chloride and 
sulphate of lead ; any lead that may yet remain dissolved is removed by sulphuretted 
hycWgeu ; and the filtrate is evaporated to drj'uess over the water-bath (Pet ten k of er). 
The residue thus obta.ined contiiins creittinine as well as creatine (Liebig).^-^. Tho 
boiling aqueous solution of the Kinc- compound is mixed with ammonia till it begins to 

in consequence of ttii? pretence of free odd, nvhicb woxild d^compoie thecreatlne, and Ipjivr a dark-brown 
■7rup^ tiarJng^ the odour oTroait ineat^iFtiklli would yinld but atury ibDialL quantity of creatine, evevt Aflcr 
loag •taDfJSng. Thilt anpeart lo be the reiii»on wl\j Ber i e H u i ( jAhreiben tjij. aS9j Mid F r^ S i m o u 
(N, Hr. Arch,, nntl. ^^3) did no| ftucc^e'(^d in pr^puirling cfc&tiiic^, 

• The JtUrAte from ]<oultry rt^nuiinii clear when Bv»naratP<S, and becomeii rotered with a fUm of oirlH). 
nale of bAriunt If too nvucli baryta- water tiai be.fii aiided ; thut tratn bt'ef becomen co?<TPd, when roncrn- 
inicd to a Chin ftjrur*. wiili a mticnu* >ciiin wlikh iwelli up in vnt> r, hut ii Itgtoluble and tnu»t ba 
rviuoted ; and Chut froin veal or hone-flcih u'Uli tV1m« which j&f l? co(itlnua.l1y reDeifcd^ ^ud muit be cou- 
tluudljr fkiicniinl off. 




CREATINE. 



97 



show turbidity, and then precipjtnt<*d with snlpliide of ammonitmi ; the filtrate i»Ta- 
pomted to a smnll bulk, and inix*H^l with til*f*olute alcohol ; and ih«? <?ryBt44]*i of crentinp, 
which separMte from the Hquid nfltr loitg staniling in the cold, arp purified by recryst^d- 
Itsation from wtLter (HeintK). Th& creatioiue remams m the alcoholic mothi^r- 

The crystals of creatitie obtAuifMl by either of theae pToaemes may bo freed from 
wmter of crystallisation by heating them t o 1 00^ C, (Liebig,) 

Proper iitt.—Ajohjdrous creatine forms a white opaque masi (LiebigV It is in- 
odoitTiia, haa a somewhat hitter taijte, aud produeoa a 8crat<?hing sensation in the 
throat ( L i e h i g )« Nentml to vegetable eol ours. ( C h e v r e u L) 

The oompoiiition of creatine dri«d at 100° C is aa folbwa : — 





C(ttculati«n. 


I 


c* . 


. 48 


36'64 


H» , 


. 9 


687 


N» • 


. 42 


3200 


O' , 


, 32 


24-43 


C-H-NK) 


" . 131 


lOOOO 



i,W 


lMh\%. 


Hd»u 


rt. 


h. 


c. 


3666 


mm 


36-30 


690 


707 


6-86 


3216 


3261 


31-64 


24-23 


23-42 


2511 


100*00 


10000 


100 OU 



a was obtained &om meat; b^ from cinco-cMoride of creatinine prepared from 
human urine, 

TheAy^ra^e, C*H"N*0',HH),fonii« perfectly limiwd priffms, l>e!onging to the mono- 
clinic system. Inclination of the clinodlagonal to the prineii>al ajiis « 70** 20'. 
ladination of the faces ccP : ooP in the plane of the orthodiagonal and principwil axis 
— I $3^ 2' (nearly). Specific grarity of the crfatuLs = 1*35 to 134. 

Creatine diasolrea in 74 pta. of waUr at 18*^0.; it is very soluble in boiling water 
and ia deposited on cooling in a mass of needles. It dissolTes in D14IO pta, of afjsolute 
a/cr>AoA bnl is more soluble in amteous alcohol ; Issolublo in cther^ 

DecompimtUmM, — 1. Hydmted creatine, when heated, first gives off ita wat*^r of 
eryKtAlliaation with decrepitation ; then meltii without becoming coloured ; ait4.^r- 
wards emits an odour of ammonia, hydrocyanic acid, and phosphorus; and lastly, gircs 
off yellow fames, which condense partly to an oil, partly to needle-shaped crystals^ 

And le»T«a a smaM quantity of charcoal (Cheyreul) 2^ The solution of creatine in 

l ^perme motmaU of poias^um is decolorised by continued digestion, without 



I mmiait 



iation of gas, the creatine being decomposed and carbonate of potasitium formed 
iebig). The squeoui solution of creatine is not decomposed by l>tt>iling with^rr- 
tt^ of lead (L i e h i g). It is not coloured by boiling wi th mtreuric « itrati (CheTreul). 



^ Creatine dissolred in strong wVrwr^ stdphiriCt phosphoric, or hydrochloric acid, is 
iHPiterted into creatinine by abstraction of nK}, the creatinine then combining with 
the idd (Liebig). But if these acids are dilute, the creatine remains untdtcred, even 
ttfler long boiling, and the solution in cold hydrochloric acid leavea, by spontaneous 
eraporation, crystals of pure creatine (Liebig). If dry h^drochl&rie acid gas bo 
passed over 149 pts, {1 at.) of hjdrated creatine heated to 100° C.» the weight first 
mcreanes by absorption of hydrtiehlorie acid ; but if dry air be then passed through 
the appftratus for some time, water is continaously given off, and the compound 
dimtaisbes in weight, till it amounts to only 154*16 pts., and contains 38 Od pts. (a 
little more than 1 at.) hydrochloric acid- Hence 36 pts. (1 at of water of crjHtallisa- 
tioD and 1 at. more produced from the creatine) bare been give a ofi^ and on tlie other 
hand, ^*Ofi pta. (1 at) hydrochloric acid have entered into combimition with the 
hydnted flNftttiie: 

C*H"NK>* + HCl « C*H^N'O.Ha + 2H^0. 



Hj-dtaileiS 
cr«tatlr>e. 



Hjdrochlorale of 
creatinine. 



131 pfs. (1 at.) of dry crciitine, similarly treated with hydrochloric acid gas, take up 
aboitt 18*04 pts., because, in this case, only 18 pts. (1 at.) water are given off for 
et«l7 30*4 pts. (1 at) hydrochloric acid taken n-p (Lie big). — The colourless solution 
of creatine in nitric acid of specific gravity 1-34 gives off nitrous fumes when bejited in 
the water-bath, and leaves on evaporntion a colouriess residue (of nitrate of creatinine^ 
"ich dissolves in waten Koparates out therefrom in small granule«« and does not 
pttate dichloride of platinum (Chevreul). — 4. By boiliag with a small quantity 
•ifta diseolved in water, creatine is resolved into sarcosino and urea, which is then 
ly retolTed by the bar}'ta into carbonic acid and ammonia (Licbig) : 

C^H'NK)' + IPO - C'H'NO* + CH*N«0. 
CrrathiM. SarecMiiw. Urea. 




this dfteompoaitton St reck or (Ann. Ch» Pharm. cxviii 151) infers that creatine 
Vot. If, H 




98 



CREATININE, 



(methyl- glycocme), i. e, aa ^^ J N. CH' V q ; 



An aqueoDi 



may bo regarded ae a compound of cyanamide (urea minus water) and sarcoBinQ 

CN \ 

ml 

■olutioD of dvatino saturated at the 'boiling facatf and mixed with crystals of baijta 
amounting: to 10 times the weight of the creatine, T^mainfl cle^up at first, but, if the 
boiling be continued, giTPa off abundance of ammonia ; deposits carbonate of bu.rium 
at the same time ; and, if fresh baryta b« added from time to time, is ultimately found 
to contain scurcely any thine but gaivosine and carbonate of barium ; and, if the 
operation ho iiit<?iTupted during the atrongest eTolution of ammonia, likewifle a little 
urea. A small quantity of another subst&noet probably urethane» is howerer produced 
at the BJime time : fov if the aleohol from whidi the sulpbato of Barcofiine haa eryst^il- 
limd o«t> be mixi>d vrith water, notitraliHed with curwnate of barinm:, filtered and 
eTapoTOt«d to a thin sjmp, eolourless necdlea ajid laminsD arc ohtiiined which reddrn 
Htm as Tery slightly, fiifio and volatilise when heated, without leaving baryta, and dis- 
eolve in water^ in alcohol^ and in 30 pts. of ether \ their aqueous solution do«j not pre- 
cipitate the a&lta of bariam, calciumt or silver, or m^utral acetate of lead, or corrofiivo 
suxiliiDate (Liebig)» — fi. The aqueous solution becomes turbid by long standing 
(i^ aooording to Liebig, it contains a tmce of foreign organic matter), and evolves a 
lickening &mmoniacal odour (Chevreul), — 6* When nitroua geut is passM into a 
solution of creatine in nitric acid, an alkali is formetl, having the composition CNH* 
(DessaiKUGfl)* — 7. When an aqueons solution of creatine i» heated with mercuric 
weide, earbonie acid is evolved, and methyluramine (CPHT^') obtained in tho form of 
ao oxalate (Bossaigues) i 

2C^M»N»0» + 0* = 2C^HT?» CfH'O* + 2C0* + H*0, 
Creatlcie. Oxaltt* of mothyl- 

ur amine. 

The same transfoirmation is effected by a mixture of peroxide of lead and sulphuric 
acid (Besaaignes).^ — B. Hot nitrtG acid decomposes creatine, yielding methyl- 
amine and ammonia (Bessaignes). — 9. Creatine heated with soia4imet gives oS 
methylamine. (Doaaaignes.^ 

Saxts of Creatine, Creatino is a vciy weak base, not being capable of neutral' 
ising the weakest acida, even when added in very large qnantity, (Liebig.) 

Sulphate of Creatine, 2C*H"N*0».80*H», and the HydrocM&raie, C^fl^N'O^.Ha, ara 
obtained in fine prisms by dissolving creatine in the prcmer quantity of acid, and 
evaporating the solution at 30° C. or m va^uo ; they are soluble in water bnt not deli- 
^nescent. (Bessaignes,) 

I^iirate of Crmtint^ C'H'N*O^.K0*H.^ — Obtained by dissolving ciyatalHsed creatino 
in the requisite quanti^ of nitric acid, and erBpomting the solution at 30^ C; or by 
passing a rapid stream of nitrous gas through water containing an excess of creatine in 
suspension. The creatine dissolves with tolerable rapidity, and a considerable quantity 
of small sbining crystala of the nitrate are formed, which, when reerystulliatHl by 
dissolving them in lukewarm water and cooling, form thick short prisma. This salt is 
leas soluble in water than the aulphato or hydrochlorate. The solution haa a very sour 
taste, and is decomposed by ammouia with precipitation of creatine. (BessaigncB.) 

From a solution in warm baryta- water, creatine cr)'{»talii&c;a on cooling without 
tak ing up any baryta. (Liebig.) 

The aqueous Boiution of creatine does not precipitate chloride of barium, basic acetate 
of lead, ferric aulphato, cupric sulphat-e, nitrate of sEver, or dichloride of platinum 

iChevreul). It does not precipitate chloride of zinc, unless it eontaina creatinine 
Heintz). Tho warm non-boiling, aqueous solution, added to chloride of zinc, does 
net throw down any cnrstalline compound, but yidda tho creatine in the separate state 
on pocjling (Liebig). On boiling the mixture, tho zinc- precipitate is formed (Heintz), 
prtibably from conversion of the creatine into creatinine. 

CTXSATXIO-XKII, C*H^»0 or C^ITJ^a^. (Liebig, Ann. Ch. Pbarm. Ixii. 298 and 
32i.—- Heintz, Pogg. Ann. Ixii. 602 ; Ixxiii. fi95; bcxiv, 125,) — Heintz and Fotten- 
kofer, in 181:4, and nearly at the samo time, discovered in human urine a uitrogeunua 
Bubstanco which fonned a crystalline precipitate with chloride of zinc The crystiilline 
tubrtjyice eeparated from this precipitate was regarded by Pettenkofer as a peculiar 
cmnpound = C"H"N*0' [plainly a mixture of croatine and creatinine], by Hointa» at 
first as an acid, and afterwards aa creatine, till Liebig, in 18-17i shoved that it was a 
mixture of cnatine and crentinine, which latter he had just before discovered 
and investigated, having obtained it by decomposing creatino with concentrated 
acids. 

Soufwe, — L In human uria«, to tbe amount of O'S per cent (FettenkoferX ao^i 




CREATINmE. 



99 



ioinrairt 
1 iUih ii 



Aoeordiiie lo Hein ts, liieiriBe in the tmne ofhon^s and other mammalia. SocololF 
h«ji found it in the uriDe of horses and of colvea. — 2. Id muficuLir flesh. An it oceura 
ift the mother-lii^uor of the cretitino prepare from flesh, nod aa dilute acids do not 

rt creatine into creatiniae, we cannot suppose that this creatinine of muscular 

ia formed by heating the decoction of tho flesh (Lie big, see p, 97). — 3. In 
. (Vcrdeif and Marcet) 
Farm a iH om. — From ezeatinep by (he action of the stronger mineral acids. 
JVtporaAofi — I. From Human urme, — a, Freah human Tinne is neutralised with 
carbonate of sodium, and evaporated below 100° C. to a syrup (till the salts crystallise 
oat, according to Liebi^) ; this aynip is exhausted with alcohol ; the filtrate mixed with 
• eooioentrated solution (alcoholic^ according to Heintz) of chloride of sine, whidi 
at flflit throws down a brown amorphous precipitate^ containing sine (phosphate of 
niie» aeooirdiDff to HeiutsX then after sererui hours^ cr^'^stalline grains ; the wbob of 
the pradpttajte, after standing for some time is coUected on a Alter (lleintz washes it 
vith VMk akohol); boiled with vt'at^r, which leayes the amomhous precipitati? undis- 
iolTed ; and the filtrate evaporated, — whereupon it yields yellow cxratals, which m ay 
be freed from adhering salts by repeated boiling with strong alcohol (Pe tte n ko f er).^ — 
K Fweh human m*ine is neatralised with milk of lime ; chloride of calcium added as 
long as a precipitate of phoiphat« of calcium continuea to form ; thi? filtrate evaporated 
till the salu Cfyiitallise out ; 32 pts. of the mother-liquor mixed with 1 pt. of chloride 
of sine dioMlT^ in the smallest possible quantity of water; the mixture set aside for 
fbordajs; and the ziRo^eompound which separates in nodules washed with cold water 
(Liebig). — c Putrid human urine is boiled with excess of milk of lime tUl it no 
loDfler giras oiff ammonia ; the filtrate is eraporatod to a eynip^ and mixed as abore 
with emoride of zinc; and the crystals which form after long stiiodingj are washed. 
(Liebig; see alao Dessaignes, J. Pbarm. [3] xxxii. 42.) 

To pioify the oystala^ it is not goo<l to use bone-charocol, which occasions great 
lose; — ^but thejmust be dissolved in hot water ; the solution mixed with ammonia till 
a pfl<eci|iitate begins to form ; the precipitation completed by means of sulphide of 
ammoninm ; the filtrate highly concentrated and mixed with absolute alcohol [ tha 
nearly white aystals of creatine and creatinine* which are oLtained b^ cooling the 
solution to a low temperature, dissolred in the amaUest possible quantity of boiling 
— '— ; the solution mixed with alcoholic chloride of rinc; and thfl precipitate, which 
on setting the liquid aside in a cold pkee, washed with aleonol. The above- 
modher-liquor of creatine, whica Likewise contains Bal-ammoniac, sil^o 
witli alooholic chloride of zinc, a precipitate which, when purified by cryatal- 
I from boiling water, yields the nine-compound in white crystals. (Heinte ; 
M0 alio Lobe, J. pr. Chem. IxxxiL 170; E^p. Chim. pour 1861, p. 25.) 
TIm iijic*eompoiind is then decomposed with hydrate of lead in the manner de- 
** * at page 96, and the mixture of creatine and creatinine thus obttiinrd, is 
' in the cold with rery strong alcoholt which dissolves the creatinine and leares 
ttne : great care must be taken to aroid rise of temperature^ otherwise some 
the creatine will also be dissolved (Neubaner, Ann. CL Fharm. cxix. 27.) 
The quantity of creatinine in urine may be Teiy exactly estimated by precipitation 
' h an alcohoHe solutiou of chloride of dnc 800 cc of urine are treated with milk 
iiaue and chloride of calcium as above ; the liquid, filtered after stand mg for two 
is evaporated to dryness over the water-bath ; the residue, while still warm, is 
«d for i or 5 hours with 30 or 40 cc alcohol of 95^; the liquid is filtered; tli« 
rondne washed with small quantities of alcohol ; the liquid, evaporated if necessary to 
a vi^me of 40 or 50 cc^ is mixed^ after cooling, with 0-6 cc of an alcoholic solution 
«f cbJonde of nnc (density 1-2), then brisldy agitated, and left to itaelf for 3 or 4 day;* 
KB ft cellar : and the crystals thus obtained are washed on a weighed filter with a small 

-' of alcohol then dried at 100° C. and weighed In this manner the quantity of 

e voided in 24 hours in the urine of a healthy man weighing 5i-6 kiL was 
to bo 1"166 grm., that is to say, 0*0214 grm- per kilogramme. 
2. F\rom Hirru-urinf^ — The urine, which Hassan alkaline reaction, is neutralised 
liydi«kchloric acid, evaporated to a smaU bulk, and then mixed with an additional 
qaantity of hvdrochloric acid; the liquid separated from the precipitated hippuric 
scifl is neutralised with milk of lime, and evaporated nearly to dryness over the wuter- 
l*^h: the nssidue repeatedly boiled out with alcohol; and the alooholic solution 
(nixrd with a small quantity of chloride of xinc : it then gradually deposits a brownisli- 
;«Uow precipitate of sineoehloride of creatinine, from which creatine and creatinine 
mm be obCuned as above, ^ocoloff, Ann. Ch. Pharm. IxxviiL 243.) 

a. From Ceived Mfine. — The fresh urine evaporated to a small bulk over the 
vativ-bath, and filtered while hot from the amorphous precipitate thereby formed, 

ei^^er a few days, a aystalUue mass coniristbg of aUantoin, together willi a 
OBantitT of plioephAte of sodium aud ammonium ; and on washing this crystalline 

B 2 






100 



CREATININE. 



maiw with <?oId watar, and reprystallking tho residue, cryatala of pure allantoin aro 
obtained. The motkeT-liquor fiUei-ed from the allanf oin is mbc(?^d with alcohol, which 
throws down sulphi'itfPi, mui.?ou3 mattor, the g^routpr part, of the phosphot^^, and a hirpo 
qmuitity of colouring matter ; and the filtrate, which ia still considerably coloured, is 
fitoed from th« renukiuder of the phoaphoric acid by means of chloride of calcium, and 
lastly mixed with a concentrated solution of chloride of zinc ; it then yieldfl a precipitate 
of zincochlorido of creatino, which coutinueg to increase for several iiya. (Socoi off) 

4. From Blood. — A oonsidemble quantity of fresh ox-blood (about Squarta) is fre€{l 
from fibrin and blood -corpiwlea by stirring, and from albumin by hf nt j then Eltered 
through linen, and oTajiomted orer the water-bath with addition of a little powdered 
gypsum, which nemo^es an ftlbuminoua Bubstanee not coagulahle by heat^ aa well as 
Bome additional blood-oorpuscloa, and pnscipitiite^ the siLponlfiablc fats. The liquid is 
then evaporated to one-fourth of ite bulk, again filtered, and tho colourless filtrate 
evaporated to dryness at a Teiy gentle heat, whereupon nesirly all the chloride of 
sodium erystaUiaea out. On treating the residue with small quantities of absolute al- 
oohol till nothing more is disaolred, and expelling the greater part of the alcohol fiy 
hcat> tho solution yields, on cooling. Boudet's seroline (Ann. Ch. Phys. lii. 337), the 
quantity of which increases on a*lilitioii of a small quantity of water. The liquid fil- 
tered ftom the sepoline fields, on a^lditton of a small quantity of aolution of chloride of 
line, sometimes immediately, sometimes after a few hours, a partly crystalline, partly 
amorphous precipitate, which is but partially soluble in boiling water. The insoluble 
portion ia resinous, and appears to be a compound of ehloride of linc with a peculiar 
organic substance; the solable portion consists of the mncochloride of creatinine. The 
quantity thus obtained is, however^ but smalL (Verde il and Marco t, J. Pharm. [3] 

5. From Mu9Ctdar Fltih, — -The mother-liquor of creatine is treated with alcohol to 
precipitate the inoaate of potaasiura or barium; the filtrate eviijKfrated over the 
water-bath ; the residue boiled oat with alcohol^ which takes up all tho creatinine, to- 
gcthrr with a little creatine, and leaves a residue consisting chiefly of chloride and 
lactate of potassium ; the filtrate mixed with chloride of «inc ; and the crystids of 
fcincochloride of creatinine, which form after a while, decomposed as above with hy- 
drated oxide of lead. (Liebig.) 

6. From Crratine. — tt. Hydrochloric acid gas is passed to saturation over creatine 
heated to 100^ in a Liebig*s drying apparatus, then dry air as long as water continues 
to esiQiipe ; or the solution of creatiup in strong hydrochloric acid h evaporated to dry- 
ness in the water-bjith. The hydrochlorate of creatinine obtained by either of these 
methods is then dissolved in 24 pts. of water ; the solution kept at the boiling heat in 
a busin ; perfectly pur^hy drat ed oxide of lead macenited in water abided to it by small 
portions till it becomes neutml or slightly olkabne, and tht-n tlin^c times as much of the 
nydrated oxide of lead, until the liquid becomes paaty from formation of oiyeWtiride 
of lead- The liquid is then filtered! and the precipitute well washed; the filtrut« 
treated with a small quantity of blood-^?harcoal to remove any lead that may «(ill re- 
main dissolved ; the liquid again filtered, and the flltrata evaporated and cooled to 
the crystallising point (Liebig). — k The solution of 1 pt. cnyitino in 1 pt. oil of 
Titriol and 3 pts. water is evajwrated till all moisture ia removed; the remaining sul- 
phate of creatinine hoQed with water and very pure carbonate of barium, till it be- 
comes alkaline; and the solution filtered and left to crystaHise. (Liebig.) 

Propfftifs. — Colourless prisma belonging to the monochnic system. Dominant 
faces «o P . eP . ce P oo. Inclination of the faces oP : oo P ao ** 69° 24' ; ota P ; oo P in 
the plane of the orthodiagonal and principal axis *= 98°^ 20'. Creatinine in the state 
of concentrated solution htis a caustic tiiste, like that of dilute ammonia. It blues 
reddened litmus, and reddens turmeric (Liebig). DissolveJ! in 1 P5 pts. of waiter 
at 16** C, and much laore abundantly in hot water; in 102 pts. of absolute alcohol 
at 16^, and moro abundantly in hot alcohol, from, which it crystallisea on cooling. 
(Liebig.) 



£^|^^A». 


From tlriufc 
4264 


From Fleih, 

41*70 


Froiin Crealtne. 


C^ . , 48 4248 


42-54 


IP . .7 619 


6-23 


6-23 


6-38 


N» . ,42 37-17 


37-41 


, , 


37-20 


. . 16 Hlfi 


1372 


J 


13-88 


c*H'N-0 113 \mm 


10000 




10000 



Ikcompfm'tions. — 1. Creatinine, under cert4iin circumstances, takes up 1 at. trntn; and 
IS reconverteil into creatine. The dilute solution of liy<lrorlil orate or sulphate of crea- 
tinine slightly Bupersjiturafed with ammonia and evaporaU'd, yields a few crystals of 
creatine (Heintz), Creatinine enclosi'd in a bottle with sumdeut water to dissolve 




CREATININE. loi 

it, yields in tbe ooime of biz xnonthB a few ciystals of creatine ; if ammonia be added 
to the liquid, the quantity of creatine prodaced is considerably greater. The same 
transformation takes place in presence of neutral salts, and is accelerated by heat 
(Dessaignes, J. Pharm. [3] xxxiL 41 ; see also Zincochloride of Creatinine, 
infra). 2. Creatinine is decomposed by mercuric oxide in the same manner as creatine 
(p. 98X yielding methyluramine (Dessaignes); also by permanganate of potassium 
(K e n b a u e r). 3. Nitrous acid passed into the aqueous solution of creatinine converts 
it, with evolution of carbonic add, into the nitrate of a very weak base, C*H'*N*0' 
(Dessaignes, loc cit; see also page 102): 

2C*H'N»0 + 0' - C^»»N«0« + 2C0« + 2H*0. 

4. Heated with iodide of ethyl and alcohol or ether, it yields iodide of ethyl-creatinine 
and hydriodate of creatinine. 

Sulphate of Creatinine, 2C*H*NK). — An aqueous solution of creatinine saturated 
at a boiling heat and mixed with dilute sulphuric acid till it acquires a strong acid 
reaction, leaves on evaporation a white mass, whose solution in hot alcohol becomes 
turbid on cooling, then clear, and deposits transparent, colourless, quadratic tables, 
which remain transparent at 100^. (Lie big.) 

Hydriodate of Creatinines OH'N'O.HI, is produced, together with iodide of ethyl- 
creatinine, in the preparation of that compound (p. 102), and remains in the mother- 
liquor after the latter has crystallised out. It is very soluble in water and in alcohol, 
and may be obtained, by repeated crystallisation from water, in large transparent, some- 
what vellowish crystals. The aqueous solution mixed with acetate of sodium and 
chlorioe of zinc, yields a precipitate of zinco-chloride of creatinine. (Neubauer.) 

IfydrochloraU of Creatinine. C^H'N'O.HCL Preparation (iL 100, 6). —Crystallises 
from solution in boiling alcohol in transparent colourless prisms, and, by evaporation 
of the aqueous solution, in transparent laminffi which redden litmus. Dissolves very 
readily in water. (Liebig.) 

ZincochloHde of Creatinine. C^H'N'O.ZnCL Preparation,— !, (p. 100).— 2. By 
mixing creatinine and chloride of zinc in the state of concentrated aqueous solutions. 
Both processes ^eld, with greater rapidity as the mixture is more concentrated, deli- 
cate needles united in nodiues, or prisms (Pettenkofer), belonging to the monoclinic 
system, with terminal faces inclin^ 82° 30' to the principal axis (K. Schmidt, Ann. 
Ch. Pharm. bd. 332). The crystals give off only a trace of hygroscopic water at 120° C. 
When the creatinine is se[Mirated from this compound by means of hydrated oxide of 
Irad or sulphide of ammonium (p. 99), more than J of it is found to be converted into 
creatine, and in larger proportion, apparently, as the solution of the zinc-compound 
used was more dilute. If, therefore, after the creatine has been separated from the 
resulting liquid by evaporation and cooling, with addition of alcohol, the mother- 
liquor containing the rest of the creatinine be repeatedly precipitated with chloride of 
nnc, and the precipitate decomposed, &c, nearly all the creatinine may be converted 
into creatine (Heintz and Dessaignes). * Zinco-chloride of creatinine dissolves 
sparingly in alcohol, but is insoluble in strong alcohol and in ether (Petten- 
kofer). It dissolves in 9217 pts. alcohol of 98° and in 6743 pts. alcohol of 87°. 
(Neubauer.) 

Chloride of zinc likewise combines with hydrochlorate of creatinine^ forming the 
compound C^H'N'O.HCl.ZnCl, which is obtained in large crystals, very soluble and 
strongly add to the taste, by dissolving the zinco-chloride of creatinine in hydrochloric 
acid, and evaporating to a syrup (Dessaignes, J. Pharm. [3] xxxii. 43). The 
solution mixed with acetate of sooium, yields a precipitate of zinco-chloride of creati- 
nine. (Neubauer, Ann. Ch. Pharm. xx. 267.) 

Creatinine also forms with chloride of cadmium^ a crystallised compound C'H'N'O. 
CdCl, more soluble in water than the zinc-compound, and sometimes appearing to 
crystallise with 1 at. water. (Neubauer), 

With eupric salts, creatinine forms crystallisable double salts of a fine blue colour. 
(Liebig.) 

When mixed in aqueous solution with corrosive suhlimate^ it immediately forms a 
white curdy precipitate, which changes in a few minutes to a mass of delicate colour- 
less needles (Liebig^. With mercuric nitrate^ it forms a crystalline compound, 
2/C*H^NK).]^N0»).Hg*0, which, when decomposed by sulphydric acid, yielas fine 
oystals of nitrate of creatinine. (N e u baucr.) 

With concentrated solution of nitrate of silver^ it coagulates immediately into a 
mass of delicate white needles, which dissolve readily in hot water, and crystallise 
oat again unchanged on cooling (Liebig). According to Neubauer, they contain 
2(C*H'NK).AgNO^).AgH). 

The clear mixture of dilute hydrochlorate of creatinine and dicMoride cf platinum 
(or of hydzochlaric add, creatine, and dichloride of platinom), yields, by slow erapo- 



102 



CREATININE. 



riitfon, tranKparent, atirora-r<»d prismR, and by quicker evaporation, pwitdps ifrhich di»f- 
iiolve readily in WHter, leas quickly in alcohol, and contain 30^53 per cent, pl&tinimi, 
wbciK'e they probably consist of C*H'>''0.HC1.RCR (Li ebig,) 

Sthrl-cniLtliiliie. C'H"NK) -= C*H'(CrH*)N*0 (Nenbauer, Ann. Cli, Phami. 
xix. 51 ; %x. 2q7 ).—Tho ifMirde of tMs base, C"H**N'OI, is produced by enclosing 311 
grras, of crt^atinine with rather more than an equivalent quantity of iodide of 4»thyt 
and about 40 per cent, of absolute alcohol, in a aealed tube and heating the mixture* 
to lOCP C. for several hours, A crj'stalline pidp ie thus obtained^ which, when purified 
by aererol recrystallisations from abKolnte aloohol, yields the iodide in long shining 
needles, very soluble both in water and io tdcohoL 

By trt'rtting the iodide with oxide of silver, carefully avoiding an exc<^ and era- 
po rating the filtrate in vacuo, a radio- cryutHlline mass is obtained, cousiating of the 

hj/dratf of t'tk^i-crmtinim g^jO + Jaq, very soluble in watiT and alcohol, 

insoluble in ether. From solution in warm absolut4> Jilcohol it crj^staUiseis on cooling, 
in fine needlefl,g^upcd in nodules. It is not deliquescent. The at^neoua solution is 
stron|*lv idkaline, h^3 a hitter taste, precipitates sesquichloride of iron and sails of 
idumiumm, and expels ammonia from its salt« when heated with them. 

The rhloride C*Ii'*K'OCl is obtained by slightly supersaturating the aqueous solution 
of the ba.He with hydrofdiloric acid, and evaporating, a^ a crystalline mnAS composed of 
interlaced needlts, veiy^ soluble in water and alcohol, inHoluble in ether. The sohition, 
mixed with dichlorido of platinum, pelds the chiori'platinate^ C*ll*'N*OCLPtCl^ in 
fine [>nsniH. 

Hydrate of ethyl-creatininc, boated in a scaled tube with iodide of ethyl, does not 
yield a comi^KJund containing another atom of ethyl, but merely iodide of ethyl-creati' 
nine and alcohol: 

Hence ethyl-creatinino may be regarded as an ammonium-base^ and creatinine itself 
as a tertiary amine, N.(C<ri'NK)) . 

Hascs produced fr&m Crcaiine and Crtniinine fty the actum o/Niirov^ Add, 

a. C'n"»N'0". (Deseuignes, Compt. rend. xli. 1258; Ann. Ch. Pharm. x«nrii. 
330.) — ^Whcn nitrons iicid gas is passed into an uqueous solution of c-rcatinioo, car- 
Wnie acid escapes, the liquid becomes brown and turbid, and after a few hours thw 
nitrate of the base, C*H'*N*0*, separates in small ycBowiah indistinct ciy^stals, which 
bc<:onie thick if left for some time under the liquid. The rcJiction is ; 

2C<H'K'0 + O^ ^ C«ff»N«0" + 2CO^ + 2H'0. 

This compound, which appears to he likewise formed in smaJl qnantitv by the action 
of nitrous acid on creatinet is a very weak base, its salts being partially decomposed 
even by solution in water. Ammonia added to the solutions t£m>W8 down the ba!*e as 
a whit^T amorphous, ta^telcHS powder, insoluble in water, but soluble in dilute acids st 
a gentle heat. Some of the salts czrstallise from their solutions on cooling. The 
hifdrocMA^mte, 2C"H»**N*0\3HCl + GH'O, forms long deeply striated prisms ; the cA/o- 
ropintinatt', which is moderately soluble in water, forms lai^ge crystals^ consisting of 
2C*H"N*a".3HC1.3RCP + 6H^, 

0. C*H*NW, (Dessaignea, he, cit,) — Produced, together with oxiiHc acid and 
chloride of ammonium, by heating the baaie a with hydrocfilorie acid ; 

Crystallises in long shining prisma or laminae \ dissolves slowly in cold water, easily in 
hot water, slightly in ether ; has an unpleasant-^ almost metallic taste ; melts and vola- 
tilises without decomposition, and bum* with flame without kaving any residue. It has 
a slight acid reaction ; docs not precipitate tlie salts of calciuni, barium, lead, coppex. or 
jsinc or cldoride of mercury, or nitmte of silver in dilute ^hition. Bessaignes regardj* 
this lx)dy as identical with that which Liebig obsened to bo produced, together with 
aareoftine, by tho action of baryta on creatine at the iRiiling heat (p. 97). Stiideler 
(Ann. Ch. Tharm. cxviii. 151) points^ out that it has the composition of metbyl*pam- 

banic acid, C'HfCH»)N»0» == 3^.(00 )''(C»0=)^CH".H. 

y. C'H*N. (bessaignefl, Compt. rend, xxxviii. 83&.) — When nitrons add is 
passed into a solution of creatine in nitric acid, a krge quantity of gas is erolTed, nnd 
on nentndTsing with potash, separating the greater part of tbo nitj^to of potassium 
by crystallisation, and adding nitrate of silver, crys^tals are obtained^ consisting of 
C*H'N.AgNO'* They dissolve in hot water, and tiflt r several crystallisations assume 
tho forta of long white necdleis. When diMSompoeed by excess of hyilroebloric acid, 



d 



CREDNERITE — CREOSOTK 



103 



tiiey yiM the nifcrate, C*H*X.HKO'» in the form of a fibrous maas of email priimt 
I living [i Yi-ry ?our tafite. The ekloromercuraU CTTStdlises in long priamH. 

Ci^/eroua Manganese, 3Chi^,2IHii<U* — A mineral fomid 
var Fredericlisrode ia the Thiiringer Wald, together with peUomciaoe imd hMumaji- 
it^. It occiirs in cry&taUo-laminar it^gregatioDs, eloaving irith modertito difitiiictii«iM 
I two diTiH^tions jmrallel to the fiidea of a monodinic pmm^ very distinctly parallel to 
F the base. Fracture uneven. Colour iron-b luck- Streidt black. Luatre vitreou% atrongest 
■ citD the perfect cleaTag|e-fuce. Opaque, Specific grarity « 4*9 to 51. Hardness a 
14-0 — 4-6. Thin kmime mtlt, at the edges oiily, when strongly heated before the 
I Uoirpip^ With borax it form* a diirk violet gliis« ; with pho«phoni8-i!alt & green 
, beooming blue on coolmp, and copper-red in the inner flam*?. Iljdrochloric acid 
^reflitiwith eTolution of ehloriuLS forming a green solution. 
Analjiefl a, b^ e^ hj Eitmmeiiiberg (Pogg. Ana. buudv, M9); d by Credner 
\lihid, IxadT. &&^y 

CaK> H*0 G*ngua 



Mn»0 


O 


Cn»0 


Ba«0 


a. 64-24 


8*83 


2373 


201 


*. 56-29 


8*58 


32-35 


3-oa 


e. 61-65 


678 


40-66 


1"48 


tL 61 06 




4273 


0-52 



076 — 



0-63 



0-25 



063 



- 08-81 
^ 101 06 
^100-46 

- 95 82 



The fonnuhi 3Cu'0.2Mti*0» requires 42'9 per cent. Cu^, and 67'1 Mn=0; tho 
r mlnM-ad often contains excesa of oxidi.^ of manganese. 

EC and AfOC&SlfXO AC1I1S« (BerzeliiiEi, Fi>gg. Ann. liii. 84; 

I 2C older, Ann, Ch, Pharm. xxxri. "243),*^ Organic acids exifiting, acconling to Ber- 

fseliua, in Tegetable mould and in the ochreous deposits of ferruginous waters. (The 

I vonl ertme is derired from k^jjvtji, a spring.) They were first obtaitiiHi from the 

\ water of Porla in Sweden. According to Berselios^ the yellow deposit which 

liormi in ^amgiiious waters eonteins these ftcids in the form of basic Mdts. They 

extracted by boiHng the deposit with potash, filtering, suporsaturating the liquid 

with flc«tic add, and adding a eolutioo of acetate of copper, as long a? a dark brown 

ferccipitAte continues to form. This precipitate contains the apocrenie acid. The 

liqaid is ftlterod, aaturnt^-Hl^ or slightly superHaturatcd mth carbonate of ammonium, 

I ttnd acetate of copper again added as long m a greenish- white precipitate ia produced. 

[The precipitation is completed by heating the mixture which contains the crenio 

leid to 80** C. ; the crenic acid is more abundant than the apocrenic. Both procipi- 

I are de<oofnpo§ed by liur^p'^nding them in water, and passing a atream of anJphu> 

Ifogeo through thi^ liquid. 

The cfwific acid is isolated by evaporating the filtered liquid in racuo. The product 

[ llins obtained still retains a obtain qtmotitj of earthy crenates, from which it may bo 

Lpeparatod by means of absolute alcohol, which dissolves the acid and leaves the salts, 

ImmL sraporating the alcohol in vacuo. As tlni« obtained^ it is pale yellow, uncrj-atal- 

" * , tnoBparont, hard^ and fiasured • its tu^t^ is acid at first, afterwards astring^'Dt. 

f With the alkidis it forma nentnd and acid saJtf, which are uncryHtaUisable, aoluble in 

rater, insoluble in alcohol, and resemble vegt'table extracts in appearance. They are 

I jreliow, and torn brown in the air from formation of aprocenic acid. 

1 Apoet^nie aeid is brown, sparingly soluble in water, more solulde in absolute 

IftleoDOl, and has a very astringent t-aste. The apocrcnates of the alkaHs reaemldc the 

^^erenatei, excepting that they are black. 

Both adds oopbce acetic acid by evaporation. Apocrenic add dissolves immedi- 
t mtely in alkaline acetates. The fe^^3us salts of both acids are soluble in water, but 
I their ferric salts arp iuHoluble, 

According to Berzehus, both crenic and aprocrenic acid contain nitrogen and crive 
[ off ammonia by dry distillation. Mulder supposes that the nitrogen found in them is in 
I the form of an ammoni urn-salt, and may be eoropletely removed by acetic acid, Mulder 
Ifepments crenic acid by the formula C^'H"0', lind apocrenic acid by C**H"0"; but 
»adds have not yet been obtained in a auMciently definite state to enable us to Hx 
[tbdr formiilffl". 

CmsosoL The principal constituent of wood-creosote (p. 164). 

C3UBOSOTS, (Reichenbach [1832], Schw, J, IxvL 301, 346; Ixvii. 1, 67; 
[Ixviu. 352. Ettling, Ann. Ch. Phurm. vi. 209. Laurent, Compt. rend, xi. 124 ; 

mix. 674. Deville, Ann. Ch. Phvs. [3] xii. 228. Gorup^Besanez, Ann. Ch. 
[pharm. Ixxviii. 231; Ixxxvi. 22;j. Vulekel, ibid. Ixxivi. 93: Ixxxvii. 306. HJa- 

a i wet I, Uiid. cv\. 33SJ. On tht Fn^parntmi of Crrosot*: : £, Simon, Fogg. Ann. 

xixii. 129. Hiibscbmunii, Ann. Cb. Fharm. xi. 40. Kone, thtd, xvi. 63. 

Krfigor, Biicbncr'ii KeperL Fharm. xlviii, 273, Buchner, fWt^. xlix. 84. CoExi, 

ibid. It. 693.) — The substjince known in commerce by the name of creoiote is often 




dii 



tQaroly lijdnite of phenyl more or less imptire ; but the true creodote extracted hj 
Bekhenba^h from wcK)d-lar is a perft?ctly distinct bcxly, and dot's not exhibit all the 
cbAnetf-rsi of hydmt^? of phenyl. It is U> the trae crco9ot43 that wood-Tin pgar, tjir-wiit4*r, 
Boot, and wood- smoke owe their power of iuresting the pofrefiiction of meat and other 
animal Buhstaacw!. The nikmecrrvsoU is dcrired from Hf4ai^ flesh, and rrwJVxy, to save, 

Prenarati&ti, — When wood-tar ia diatilletl till the re«idut> a<*quire8 the consistence of 
ft piUuiy maeii, the liquid collected in the reeeirer is formed of serenil distinct layers, 
the lowest of which contains the creosote. On saturating it with ctirl^onato of i^oditiiQ 
and leaTing it at rest, u yellomish oil riBcs to the surface. This oil is decanted, and 
recfdfied in a glass retort^ the lighter portion of the difstillafe being rejected and the 
heaTier portion collected and ignitod with potash-solution of c^peciflc gravity 112, 
The creosote then dissolves in the alkaline liquid, while the hydrocarbomi with whieh 
it is mixed remain undissolved. The alkaline solution is decanted and boiled for 
some time in contiiet witli tlie iiir, to resinise a foreign Buls«tunee dissolved in the 
potajeh, after which the liquid is filtered and the creosote set free hy addition of sul- 
phuric acid. The creosote thus obtained is not yet pure; it reqtiires to be again 
Jis(illed severd times with alkaline water, then disMolred in potsi^h, to free tho 
creosote from iniioluble hydrocarbons, and separated from the alk aline solution by 
sulphuric acid. Theaa (H>eratioiis must he repeated till tlie i?Teosote dissolves in potasb 
without residue, alter which the creooote is to be finally difitiljed at 200° C, and dked 
over chloride of calciam. 

PnjffTties. — Creosote is a coloarlesa, oily, strongly refracting liquid, having a dis- 
agreeable penetrating odour like that of smoked meat^ and a buruing tatite. SpeciJle 
grj^vity 1037 at 20*^0. (Reichenbach), 1040 at 11*6^ (Gorup-fie^anea), 1076 
at 15-5^(Volckel). It does not solidify at -27** C. Bofl»at 203^lReiehenbacb); 
between 203 -^^ and 208*^ (Qorup-Besanez), and distJlsiugr^at part witho^st alteiu- 
tiou. When pure it does not become coloured by exposiire to the air. It buma with a 
smoky flame. Does not conduct electricity. 

Creosote is sparingly soluble in water, but mixes in all proportions with alcohol, 
etlier^ bisulphide of carbon, napbtlia, and acetic ether. It die^^ulveji sulphur, phos- 
phorus;, selenium^ oxalic, citric, tartaric, benzoic and stearic acids, re«iins, and t^everal 
colouring matters. With the aid of heat it dissolves several mt-tallic salts, r. ^. the 
chlorides of ealeium and tin, the acetates of potassium, sodium, ammonium^ zinc, &c^ 
and deposit* them in the crytttAlline state on cooling. 

It imparts a blue colour to ferric saltM^ and reduces nitrato of silver, and the salts 
of mercur if ^ gold, and platinum. When dropped on recently prepared oxide of silver 
it produces a kind of explosion, the silver beio^ partly reduced, and oxalate of silver 
Ibrmed, together with several resinous compounds. 

The composition of creosote is not yet definitely fljiei Tho foUowing are the 
analyses which have been made of it : 





6 


til faff. 




G<}Tup.B 


Eunei. 




c . 
H . 
. 


. 75-72 
. 7-80 
. 16-48 
10000 


74-53 

787 

17-60 

100i>0 


76-32 

784 

1684 

10000 


75-72 

7-94 

16-,14 

100 00 


74-78 

798 

17*24 

100*00 

VolcJtel. 


74-68 

7*84 

17-48 

10000 


c . 

H . 
. 


. 72-30 

. . 7*00 

. 20^10 


72-54 

7-60 

19-8G 


72-92 
8-lG 
18-92 


72-48 

7*04 

20-48 


72-53 

7-10 

2037 


72-35 

7-16 

20-49 



100 00 100-00 1 0000 100 00 100 00 100*00 

Gomp-Besaaes deduces from his analvses tho f«>rniuLi C"H'*0* (calc« 76-47 C; 
7'84 H). Toldtel gives the formula C'*H'*0' (72 72 C ; 7*07 B) ; neither of these 
formulae ai^rees well with the analyses. According to Hlasiwetz, creosote is a com- 
pound ether derived from an acid, C*H*'0', which » when tj^'ated with bases, forms 
salts having tho composition C*fi"MO* and yielding the acid itself when distilled with 
dilute sulphuric add (see p. 105). 

peeompomiianB, — Creosote is decomposed by chlorine, with evolution of hydrochloric 
acid and formation of a chlorinated compound, which is decomposed by distillation. 
Bromine is absorbed in large quantity by ereowote, yielding, according to Deville, a 
ciystalline acid, having the composition of creosote in which half the hydrogen is 
rephiced by bromine. Iodine dissolves in creosote, forming a brown liquid. 

When creowte is acted upon at a ^il^ heat by a mixture of hifdrochl^fric add and 
tMoraU of pot<i4nHm, the action being continued for serotal days, and arrested as 



CREOSOTE. 



105 



•oon M An abiisidiiiit erolution of elilorino Ukes place, a ciyBtalliiio masu 19 obtained 
fromwiueli cold alooliol extract s a substanct* cryetallisiog in large rbomboidal tables, 
iMTiag another oomponnd in tbe form of yellow scalej^. (Gorup-Bcsunez). 

The rhomboidal tables give hy analysis 39-8 per cent C. and 19 H, -which Gonip 
rcprwente by the formula C"H'CPO», dm^atin^ tbeeomponnd a** pnjtacldoroT^Hn. 
Gcrhardtp however {TraiU, iiL 24). prefers the formubi CHKn'O' (cak. 40 pep 
cent cu-boQ, aind 2 hydrogen) ; according to which it is homologous with triohlon^tii- 
oaiie. The yellow scales fi^xe by anaU^is (mean) 367 C, \o H, and 606 CI, which 
Gonmrepraiezit^by the formula C"H*C1»0* {he:[acMoroxyUn), whib Gorhardt giTea 
the fixrmida CH*C1*0^ homologous with tetrachlopoqninone. When the yellow 
■cftLn ftfe imspended in water and sulphurous acid ^rg^ passed through the liquid^ 
the acftlee are couTerted into brownish-white fonip-sided prisma, which dissolve in 
a mixture of alcohol and etJier* yielding a yellow solution, which, by spontaneoua 
eraporation, deposits lougj violet niMydlea and reddish prisma, the latter containing 
aliont the same quantity of carl)on as the yellow scalesa, but more hydrogen (2 '23 to 
2 39 per cent). Hence these produt^ts would a^^pear to be related to the yellow a<jales 
ID the same maimer as tlie chlorinated hydroqiunones aro to the chlorinated qui nones. 
All f.he«e oompgimds require ftirther investi^ition, but their formation is sufficient to 
»bow that ervoeote from wood-tar is a very tlitferent thing from hydrate of phenyl, the 
•o-eaUad cval-tor crmsotr. 

OriOiOte partakes of the nature of an odd ; it dissolves in caustic alkalis, and ia 
dieairaoivd by potassium, with elimination of hyilrogen. Two potasaiumHBaltB have 
iMiOmilied^ iiIbo aodium, amnionium, banum, lead, ethyl, and beusoyl-salts. 

FttM f i um^»aU9,~^ Neutral, CiPKO^SH^O. Obtained by heating creoeote with 
•olid kydratfi of potasffiuiD to about 130° C. in an atmosphere of hydrogen, and crys- 
talliiing the product from ether. It is then obtained in thin soft prisms or scales, of 
dialing whiteness and satiny lustre. It dissolves readily also in water and alcohol, 
crystallimng from the aqueous solution in soft interlaced needles. When thoroughly 
freed from mother^liqnor by pressure and dried, it may be preserved without alteration ; 
Otherwise it quickly turns bluish-greeo, aod ultimately brown on exposure to the air. 
The same ia the case with all the oiposote-saltei i hence tlie necessity of excluding the 
atr dtiring their preparation. —0. Addmlt^ 0"H*KO*.C?H"0^ Obtained by treating 
creosote with potassium in an utmoephere of hjdrogeo, and erystalllBing from ether. 
Bes«!nibles the neutral salt in ftppeanmco and in most of its properties, but is decom- 
poeed by water. (HlasiwetK.) 

86dmm*9alU,-^T^)090%^ behaves with sodium and hydrate of sodium much in the 
MOMt msimer us with potaosium and its hydrat-e ; but the sodium-salts have not yet 
been otitained in definite form. (Hlasiwetz.) 

Barium-9al(, 2C?*H*BaO*+ BIPO.— Prepared like the nentaul potassium-salt. Forms 
d#n|ing white scales, having a satiny lustre, quite inodorons, and permanent when 
pore. Gives off ita water at 100^ C. (H la s i we t «.) 

Lead-salt, 4C*H*PbG«.Pb»0 + 2H=0*— The neutral potaesinm-salt mixed with acetate 
of lead yields a bulky white precipitate, whlcli, when dried in vacuo, exhibit^a this com- 
pontioo. (Hlasiwetc.) 

&hyf-o^*'"^^''"^ f!*H''(CH')0'.— Obtained by heating the neutral potasainm-salt 
with iodi in a sealed tube, distilling^ removing the last traces of iiwiine by 

agitatiou r, and rectifying. Oily liquid, having a slight yellowish tinge and 

fatot ■romatie odour. 

A hmxi^yi-compound, CTI*(C'H*0)0^ appears to be fbrmed by treating the neutral 
poCasnnmWt with chloride of benzoyl. (H lasiwetz.) 

Ormm^^im C*H"0*.— By decomposing the neutral potassiiun-salt of creoMte with 
diliite mlphuric add, washing with water, rectifying, and collecting the portion which 
distOs over at 219° C. {which is by far the larger portion, amall quantitie,'* only dis- 
Hllii^ it lower and at higher temperatures), a colourless oil is obtained, agreeing in 
*tioii with the formida C*H»*0* (69-6 C, and 7*2 H). It is of the consistence of 
__^ i«lkscts light fltronely, has an aromatic odour like tliat of vanilla, and burning 
anhydrous; but little altered by keeping. Specific gravity 10894 at U^ C. 
Vsponr-d^nsity 4-98 (by calculation to 2 voh§, 4-79), It is not more soluble in water 
ikmxk ereoBote ;' mixes in all proprtions with alcohol, ether, glacial acetic acid, and 
aJkmM^j ^ Xan* In a freeadng mixture, it becomes viscid, but not solid. It rtnluees 
liinetm 0i mWer, pfodnetng a specular deposit of the metal. Does not unite with the 
Kid sulphites of the alkali -metals, but forms with ammonia, either in the state 
of ew or in strong aqueoua solution, a cnrstflllino salt, sparingly soluble in wat^Ti 
aadhcvhig the composition C*mNH*)0«.C?ff»0«, analogous to the acid potassium- 
«lt akrr« described* With potash and baryta it behavee like creosote, yielding the 
Mly CfPKO* Mid OTI*BaO» ; the preparation of which is moreover much <^^«r ^*» 
this oil thaa 'rith crroet^to. Bromine acta violently on it, forming a ciysti '" 



106 CRESOTIC ACID— CRESYLIC ALCOHOL. 

pound, contaimng C"H'*Br*0*, Tho same compound lb formed by the acCioD of 
bromine on crude creosote; it doe« Dot however Bolidiff nt once, but forms a crvBt*!- 
line pulp, from which the puro compound may be obtained by disaolving the pulp iu 
& imiall quantity of ioetic iicid, leaTing the aolution over night, and presiing the 
deposited crjfstjda to &ee them from mother-liqnor. It is formed by the replacemeut 
of 5 aL hydrogeJi by hromin© in & double molecule of creosoL 

THchioroereosoi, C*H^C1'0', is formed by introducing creoflol into a large flmk Jelled 
vitb chlorine. The whole aoUdifies in about 24 bours, and the product may be 
purified by crystallisation from acetic itcid (Hlusiweta.) 

It appears then that creosote cousisti! mainly of an oil capable of forming salta with 
baaoB^ and having the compoaitioD C'H^H)^ This oil (creo^ol) ia liJkewiae contained 
m the product of fhu destmetive diatiUation of gu^ae resin— this product comiistiiig; 
Bceordmg to Hlasi wetx, of gw^acol^ C1SS)\ and the homologoua compound, creosote- 
gvajffcol or creo3oi, CH'^oC Creooote itself ia probably a compound of the form 
C'H*(It)0' or C"II'*(B)0\ in vhieh B denotes a ndick fir«« from oxygen. (Hta^i* 
wete, ioc. d(.) 

cmBBOTZC ACm. C*IPO»«^ g yO. {Kolbe and Lautemann, Ann. Cb, 

Pharm. cxv. 203.) — An acid isomeric with carbocresylic acid^ produced by the action 
of fsodium and carbonic anhydride on cresylic alcohol (C'H'O + CO' = C^H^Q*). Tho 
resulting mixture of caTboCTceylate and creaotate of aodium is treated with hydro- 
chloric acid, whci^ebj the carbocrosylic acid ia reaolTed into carbonic anhydride and 
CFefrUc alcohol, while the cresotic acid remains undecomposcd^ und may be waahed 
out by means of a strong solution of carbonate of ammonia, the liquid on eTaporation 
yielding thp pure acid iu fine large prisms. The acid diBsoIves sparingly in water, 
easily in alcohol and ether. It molta at 1£S° 0. and solidijics at 144'^. By mining it 
with aalicylic acid (which racltB at 169°), a mixture of lower melting point is obtained: 
a mixture of 1 pt, creaotic acid and 4 pta, aalicylic acid was found to melt at 139°. 

Cresotic acid produces a deep violet colour with eesquidhloride of iron. When 
heated with ci^mtic batyta^ it is resolTed into carbonic anhydride and creayUc alcohol 

CRS9OmA.CBirZ0 ACZZ>. C"H"0"?— An acid produced by the aetion of mono- 
chloracetic iicid on cresylate of sodium. Its copper salt, C'H'CuO* + nq. , is green, and 
sparingly soluble, (HeintB, CerL Akad. Ber. 1860, p, 464.) 

CSZSSt OI^ OF» Tlie herb of Lt-pidtum ruder ok and the inodorous seed of 
Ixrpidium rndtraliif L. sativum, and L. campr^ire, bruised and macemted in wateiTp yield 
by distillation a milky water, from which, by repeated fractional rectification in glasa 
Teasels (copper would exert a decomposing action), a yellow oil may he obtained. This 
oil, after frirthcr rectification, is colourles^i, but turns yeUow again on exposure to 
light. It is hearier than water, neutral exhibits the refreshing but somewhut alliaceous 
odi)Ujrand biting taste of water-cresses, and, when its Ti^Knir is inhaled in rather laz^ 
quantity, produces diyneas in the throat and headache* II cannot be distilled undo- 
composed without water. By oxidation with nitric acid, it pelds sulphuric acid. 
With mercurous nitrate it forms a black precipitate of sulphide of roercmy; with 
corrosive snblimate a while ^recipitiite i with nitrate of silver, sometimes whiti*, 
sometimes Mack ; with diehlonde of platinum in alcoholic solution, an orangi^yellow 
precipitate? after u while. Aqueous potash and ammonia 1uit& DO action on Uua oiL 
It di^nolves with red colour in oil of vitriol, and may be s^ar&ted again by water. 
It disHolrea alowly in water^ readily in alcohol and ether. (Fleaa^ Ann, Ch. Pharm. 
Iriii. 36.) 

The frtsb tt^aves of Lepidium lo^folium yield by distillation with water, a neutral 
oil heavier I bun water^ together with a milky, strong-smelling and shitrp-tasting 
water, which loseit it^ sharpness by exposure to the air, and likewise in a few hours 
itft4?r being miabed with chlorine (whereupon it precipitates chloride of barium) ; it 
gradually Ibrmt a black ^rccipitiite with nitjato of silver; blackens metallic silver 
after a while ; ft&d ia deprived of tta taste and odour by chaicoal powder. (3 1 e n de 1, 
JDisf. 4^ tm^dine nonnuU. iv^r^ii6. Tubingen, 1805.) 

CRSft-rXiXO iLXiCOBOXi. Htfdrate of Crrsyi. CH»0 » C'E'. tt O. -Th is alcohol 
bomologous with hydrat*? of phenyl wa» dijicovered m 1864 by Williamson and 
Fairlie (Chem. Soc. Qil J, yii, 232), and further investigated by Duclos (Ann. Ch, 
Pharm. cii. 136). It occurs in vuriable qnaotity in tho so-called coal-tar creosote, and 
is obtiiined by mibjet"tingthe portion of that liquid which boils betwrcn 200^ and 22tP C. 
to fractional distilktion (F ai rl i e). It likewise exists, together with hydrate of phenyl 
and other compouuds, in the tar of fir-wood^ and is obtained tb*. re from by tr^^ating tho 
oil which pasaea over in fractional distillatiou between loO^ and 220^» with weak sodu- 
ley, to separate hydrocarbons, supcrsaturatiug the alkaline liquid with sulphuric acid, and 
repeating the treatment with soda-ley and sulphuric acid, til the oii becomes perfectly 



CRESYLIC ALCOHOL, 



107 



soluble in the alk;ilme liquid. The oil thu» ol)ttiid<*d is a mixture of phenylic and 
cres^yUc alcohola, wbidi are Mptamtod bj fimetionaJ distiUatioo, tfi*? fornior boiliuir 
at 187°C. ^ 

Cre«ylic alcohol is a colourlosa, strongly -rcfrftcting liquid, wliich boils al 203° C\ in 
the air (the «4me as wood-tar creosote, p. 104), and at 200" in an atmoaphero of 
hydrogen. Analysis gave 77*4 to 777 ]por cent, carbon, and 8*06 to 2-20 hydrogen 
(oilciUaittOQ, 77'8 C, and 7*11 H). It ia isomeric with benzyllo alcohol (i. 678). 

Cresylie alcohol is aliffhtly solublo In wat^^ and znixos in all proportion a with 
^eoktd and €tker. According to Fairlie, it is quite iaBolnble in amjjiojtia ; but accord- 
ing to I>iiclo8, it diaaolrea in ammouia as eaeiiy as phenylic alcohol. 

Cftiylic aWhol is deoompogfld by rt!peat«d distillation, a portion being apparently 
oniTierted by the oxidising action of the air into hydrate of phenyl, C"H*D ; but in an 
atmosphere of hydrogen it may h« diatilled any number of times without alteration. 
Strong nitric acid at ordinary temperatures attJicks it with explosive violence ; bnt 
when treated with well-cool«»d mtric a<dd, it yields a red solution containing t rin i t ro - 
cresylic acid, C'H*(NO')"0, homologous with picric acid. With dilute nitric ac^id 
it forms only a brown tany mass (Fairlie); according to Ducloa, the product ia 
fflononitrocresvlic acid. With strong sti/pAuric aeid^ cre^ylic alcohol becomes 
rose-coloured, anil forms snip hoc reiy lie acid, C^H'Q.SO*. Vfith pent^icMoride of 
pko9pkoms, crcsylic alcohol yielda chloride of creayl, C'H'Cl (boiling at 197^.), and 
phosphate of cr<?8yl, wh i ch latter is con vert led by acetate of potassium Into acetate 
ofcresyl, and when distilled with tih^laUof potmtium^ yields creflylate of ethyl 
trM*,C^H^O, and phosphate of potussiunL Mixed with an equal bulk of strong 
poUuh-ltu, it forms, in the cou»e of 24 hours, a few imall cijstals, apparently con- 
sisdnff of erssylate of potassium, C^^KO (Patrltc). In contact with chhride 
€f ciSeium or ekhride m ginc, it appears to be converted into phcnybc alcohoL 
(Gladstone, Chemical yevts, ii. 98.) 

Cresylic alcohol, treated with potassium or sodium^ gives off hydrogen and forms 
a brownifih mass, which, on cooling, solidifies to a mass of slender needles of cresylate 
of potassium or sodiimi, difficult to purify by crystallisatiDn from ether (Buclos), 
Crvsylate of sodium treated with monochiontceUc add yields cresoxacetie aoid, 
(Heintx, p. 207.) 

Derivative* of Crts^lic Aleohol^ 

WitroereayUis Actd, C'H'^O* = *^'^*^^^'^io.— When very dilute nitric add 

is gradually added to an aqueous solution of cresylic alcohol heated to 60° or 70'' C^ 
the liquid acquires an aromatic odour and yeUowiah-brown colour, without giving off 
red vapours, and ultimately deposits nitrocresylic acid in oUy drope^ which ttink to 
the bottom of the veescl ; they ore wajshed with water and dried in vacuo* 

Kltrocreeylic acid is a yeDo wish-brown syrupy liquid^ inodorous, bitter, easily soluble 
in aleoihol, colours the skin yellow. It appears to unite with alkalis. (Ducloe^ ioe, eii.) 

DlnitrocresyUo Acidp C'H^K^O* = ^ "^ -^'^' O.— This add is preparcd, not 

directly from oresylic alcohol, but by the action of nitric acid on sulphocresylic acid. 
A sulutioa of 1 vol, gulphocresylic acid in 6 or 6 vuls. water, or an equally dilute 
ttiluUoii of cr*«ylie alcohol in a Hmall quantity of sulphuric acid, is heated with a 
small quantity of nitric acid diluted with it^ own bulk of water ; the liquid is filtered 
^m a resinous bodv which Ht-paratea on cooling; and tiie tUtrate is heated to boiling 
with addition of nitric acid. Uiaitrocrctfyiic acid then separates as a yellow oil, 
which dissolves in aleohol» but does not crystalline hy evaporation. When filowly 
heated, part of it appears to sublime undecomposed ; when quickly heated it detonates. 
i^Dttolos.) 

Dinitrocrem/laU of Ammonium is easily soluble, but difficult to ciystallise. (B uclos.) 

TiliiiiwMsreayllo Add, CH*N»0' - *^^*t^'^>'| 0.— Discovered by Pairlie. 

moTM fully investigated by Duelos, Homolocons with trinitrophenic or picric acid. It 
is obtained — 1. By adding fuming nitric acid in small portions to coal-tar creoaote con- 
tuning cre^lic alcohol, iv\ a vessel anrroundcd with ice. The liquid then aaanmes a 
deep red coJour. and after the addition of a volume of nitric acid eqaal to that of tho 
ereosote, separates into two layem, the upper dct^p red, the li>wer black and tuny ; 
the upper contains the trinitrocrcsylic acid (Fairlie).— 2. By heating a dilute solu- 
tion of sulphocresylic acid with nitric acid, filtering from the resinous body which 
Bfparates, again beating the filtrate with nitric acid, and evaporating. The dinitro* 
ermlio acid which first sepamtes, is then converted, by the coiitinut^d aetion of tho 
nitnc add, into trinitiVH*re«yliL» ueid, which is found,, to^efhcr wifh oxalic acid, in tho 
ciyitalliiie rc&iduu obtained ou cooling. The oxalic ncid is removed by wabhiug,, and 




108 



CRICIITONITE— CEOCIN. 



thp trmitrt>cp<«ylic acid m&j be obtainwi in the oyBtalliiie form by soltition in alcohol 
and eiraporatJon in vaciio. (Dnclos.) 

Trinitrocresylic acid cryHtallis&s in jellow ncedlei^ soluble in 449 pta. of ifater at 
20^ 0, and in 123 pta. at 100=^ (less soluble tliert^fore than picric acid)v The solntion 
haa a flae yellow colour, reddens litmus, and iinpartii a yeDow stain to wool and silL 
It duusolrca edeoholf ethcr^ itnd benzene. It la separated from its aqueona solution by 
most mineral acids, hut diseoWea in exc^aa of nitiic acid mor^ easily than in wat4*r. 
When heat«d a little aboTO 100^ C, it melta to a reddiah-yellow oil, whicli fM>lidifiea m 
the crystalline fbrm on cooling. At a higher temperature it dcfiograt^ like pime 
acitL (DucloB.) 

With solution of chloride of Lime, or with hydrodiloric add and dilorate of potaaiBinni, 
it emits the odour of chloi-opicrin* (Dncloa,) 

Tnniirocr^sylate. of Amnwnium^ ^ j^ttJ [ 0» crystallises in yellow needles 

easily aoluble in wat«r, less easily in alcohol; they deflagrate when heated, (Dneloe.) 
Tnnitrocjrsy/atf of Lead, 2C'H'Pt>(K0=)*0.Pb«0.— Wlicn a boiling dilute solution 
of acetate of kad is mixed with trinitrocreBylate of ammonium, thia salt sepamtes from 
the filtrate on cooling in microscopic needles which are moderately soluble in water, 
and d<-'tonat-e when heated. (Ducloa,) 

Trinitrocresylate of Poiassium^ C'H*K(NO=)*0, crystallises in smoU orange-rod 
needles which arc raoderatjely soluble in water (Ducloa) ; sparingly »oltible in cold, 
easily in hot water (Pairlie), and detonate strongly when heated, (Duclos.) 

fiulpliOGreaxU«i of CresyUttlplmrio Acid, C^H*01S0».— First obt^cd hy 
Fairlie ^ further eiamined by Duelos. Not known in the free state, Crwiylic alcohol 
is mixed with strong sulphuric aciii, the liquid left to stand for about 24 houre at 
tiljout 60^ C, and then mijtcd with water, which doci not separate anv oil-drops. This 
liqtiitl, saturated with carbonat4> of lead or ciirbonate of barium, and carefully evapo- 
rated, at last in Tacuo, yi<»lds the corresponding sulphocreaylates. 

The barium-sali, C^H'BaO.SO*, is colourless, amorphous, aud eaaily decern posildc^. 
The lead-salt, C^H'PbO.SO*, gradually dries up to an amorphous,. celouiiMi maas, which 
decomposes at 140*^ C. 

CXXCHTOlffZTli. A varietv of titaniferous iron, found at St. Cristopbe, near 
Orsans, in the Xl't^partemout d'lsi^re (Dauphini)^ and regarded aa a subspedlea of 
ilmonite {g. r.) 

C&XS9IT&. Syn. with ErriLB. 

C&ZTBMtfBS MARITXMUM. Srn-ftnnd. An umbplHfcrouB plant, growing 
^\i the seashore, contiiiniug volatile oil and free act tic acid. (Laviui, (leiger's 
Hiigaz. iv. U8. 

CRacSTXW. See CnociN, 

CXtOCnr. C»II^*0'», or C"H«0»,— The eolonnng matter of Chinese yolk»w 
btrries^ the fruit of Gardmia gru^idifiorti, Discovered and partly examined by Mayer 
in 1858, more particularly by Rochleder{J* pr. Chem. h-i. 68), wlio regards it as 
identical with a subfiUnce which Quadrat obtained in an impure state from safiroUi 
and to which be aseiirno.! '^- '^ —iiila C*fl"0*'. 

To prepare crocin^ fli' How berries are boiled with alcohol ; the eicpressed 

liquid is filtered, and tliL ■ vaporated ; the remaining aqueous !*<dutioD, which 

deposits a liquid fatty acid and a crystalHne suhstanee, is filtertKl, diluted with wat«r, 
and mixed nith a large quantity of hydrate of alumina; the liquid, filtx^nnl aft^^r 
standing for several d»ya» i« precipitated with basic acetate of lead ; the reddish- jellow 
precipitate is quickly collected on a filter, waahed, suBjientled in water, and decom- 
posed with siUphydric acid, the colonring mftttej* then separutin^, t^ij^pther with the 
sulphide of lead ; the precipitate, after washing with water, isweli boiled with alcohol; 
and the filtrate is left to diy up in vacuo over sulphuric acid- The rasidue is then dis- 
solved in a small quantity of water^ filtered from a smtdl quantity of separated aulpbuTj 
and again evaporated. 

Crocin thus prepared yields, by tritnration, a bright red powder, easily soluble in 
water and in alcohol, the eolations having the colour of disaolved chromic acid, and 
forming an orange^cobured precipitate with lead-salts. The concentrated aqueous 
aolutjon mixed with strong sulphuric acid assumes first an indigo-blue, then a violet 
colour. The dilute aqneotis solution boiled with dilute sulphuric or hydrochloric acid, 
is resolved into croc e tin, which separates on cooling if the solution is not too dilutev 
and a colourless nncrystallisable sugar (amounting to 28 '2 per cent, of the crocin), 
whicli remains in solution : 



Crwrta, 



smo 







CEOCIDOLITK^CROCONIC ACID, 



109 



Crpcetin, C»*Hn>", or C^iT^O'^— To obtain this snbrtjuice puiv, thu crociii should 
be boiled with the acid in au utmuspbeFe of bydrogieii or oarbooio ttd.d^ a» botb crocin 
iknd crooetui eaiilj absorb oxjgi^n. 

Croeetin is a dju-k red amorpboua powder^ idightly soluble m water, easily in alcohoL 
It funis bltie in stUpkurie acid, like cpocin. Its solutioa forms a yellow pri'cipitato 
with Uad*iaiU, Stufi mordanted with ttn-salt acquiie, by boiling in a Bolution of 
crocetin, a dingy greenish ycUow colour, which by (:r«Htni<«nt with ttmnionincal vinUr 
ifl eonrerted into a brilliant yellow colour, tinalttred by H^ht and air, Tbo yellow 
robes of the Chinese mandarfne are dyed with the frmt of the Gardenia, (Handw* d. 
Chem. il 2»» Aul iu [3] 226.) 



I (from Kp^Hit, woof). A silicate occurring in asbeatos-like fibresi, 
also roaasivt", in the Qritma country » beyond the Orange river, South Africa, and in the 
mlcaceons porphyry of Wakenbaeh in the Vosges, Bpeeific grarity ^ 3 '2 — 3*266. 
Qardness — 4. Coloor and streaky lavender-blue to leek-green. Opaque. Fibrt^s 
somewhat elastic. Melts eiasily before the blow-pipe to a black, shining, opaque, some* 
what frothy glass^ attracted by the magnet Single fibres melt in the tlame of a tipLrit^ 
lAni|). With borax it forms a green traasparent bead, changing to brown on addition 
of nitre. 

Analyses: a. from Africa, by Klnproth (Beitr. Tii 237); f>- fix>iii Africa, by 
Stromeyer (Pogg. Ann, xxiiLl53)] c. from Wakenbach^ by Be lease (Ann. Min. 
[3] 3L 307)l 



8tO* 


FeK) 


MnO 


Mg*0 


Cu^O 


Na«0 


K»0 


H»0 


CI 


P«0» 


a, 60 


40-5 





. — 


1*5 


60 





30 


. 


, J. 


IK 61112 


34-08 


010 


2-48 


003 


707 


. , 


4-80 





^^ 


<R. 53-02 


25*62 


0-50 


10-14 


1 10 


6*69 


0'3& 


2*62 


0-51 


0'17 



Prom tbeee analyses, Rammelsber^ {Miner alchemie^ p. 476) deduces the formubi 
7M*0.98iO' + (14 . . . . 3)H'0. Taking the krger amount of water, and ftuppoalnij 
2at to be basicj this formula may be reduced to <M'*H*)Si''0 " + aq., or OR'SiO* + aq., 
whieh ia the formula of a metasilieate. The mineral is pcrlmps formed from aoda- 
hombleDde (arfVedsonite), by abstraction of Lime. 

A somewhat similar mineral occurs at Stavem in Korway, 

CmOCOZSXTE, Native cbromate of lead (1 934). 

CBOCOVIG Acn>. C*H^* = (C*O«)".ir.0'.^(L. Omelin [1825], Pogg. Anu. 
ir. 37; Handbook, x. 388. Liebig, Pogg. Ann. xxiiii. 00. Heller, J. pr. Chem. 
xii-230; Ann. Cb. Pharm. xxiv. 1; xxiiv. 232. Will, Ann, Ch, Pliarin. cxviii. 
177,) 

Wliea the componnd of carbonic ozida and potassium, obtained by pusing the diy 
gan oT»T melted potassium, — or, as a secondary prodoct, in tlie preparation of potassium 
by heating carbonate of potassium with charooad — is immersed in water^ inflammable 
gaa is evorred, and aatrongly alkiiline yellowiah-red solution i* formed, whichj when 
left to evaporate at a gentle heut, bect>mes p.<ile yellow and deposits long yellow needlea 
ofcroconateof pota^itium, while o x a la t o of potaswinnn remaiuft in the mother^ liquor. 
Thfiee two salts are not, however, the immediate prodncts of the action of air and 
wster out the compound of potassium and carbonic oxide, their formation \mn^ pn^- 
ttidad by that of a red Hdit, the rhodizonate of potasainm, the evolution of whieh de- 
eompoeai, during evapomtion, into croconate, oialate, and probably also cjirlxmate of 
polaaifmi. The relations l>etw«ea these several products are not exactly known* 

The black mass produced in the pre|varation of potassium should be expoeed to the 
airlbr tefreml weeas before it is difisolved in water; it then gradually aoquii«e a red or 
yellow colour and dissolves in water without explosion; but if It has been exposed 
to the air for a few hours only, it takes fire in «>ntact with water (beemise it contains 
fr^ee potaaaium), and produces a vioknt explosion whieh shatters the TeiteL 

Croconic acid is obtained in the free stiite by digesting the potftsstuiD-salt with a 
mixture of suIphuHe acid and absolute alcohol for several honn, then filtering, and 
leaTing the aolutioo to evaporate. 

It cannot be coaveuienLly prepared by decomposing the lead-salt with sulphuric 
■eid, iSfi the decompotiitinn ia never complete, or by dt*cotnposing the lead or coppsf 
salt with sulphuretted hydrogen, aa in that case peculiar sulphur»coropounds are fonmsd 
which are troublesome to separate* 

Croeo>nic acid crystalliBes in iinliydroiis, orange-yellow, transparent prisms and 
enuinleB (GnieUn); in golden-yellow laminaQ or granular crystals containing 
C*K*0* > 3H*0, which become opaque and cnunble to a yellow powder when kft 
over oil of vitriol, and more quickly when heated to 100^ G, (will). It is ioo- 
doTOQi^ has a rtroogly add taste, and reddcna litmus. It dissolves easily in water. 



110 



CROCONIC ACID. 



form in g a yellow Bolatioa, whicli gradually becomes colonrleaa ; easily ulao in akohoL 
(Omelin.) 

Cpf^conic acid is not tdtered by a temperaturiG of 1*){>° C, but whon moM !?trongly 
fjeated^ it ^ves nff whit-o ftad yellow irritiiling Tapours and leaves a small quantity of 
etiMily comboHtible charcoal. In combination with potaah it is quickly decom posted 
by permanganate of potasnum m presence of aulphnnc acid, being entirely converted 
into carbonic acid. (WilL) 

The Bolution of tho potassLumosalt is complet^'ly decoloriaed by niirie acid and by 
cUorim (Qmelin^ Liebig), with errolution of nitric oxide free &om carbonic odd in 
the former caae(G'raelin, Will), without evolution of gas in the latter (Will). Id 
botk cases a new Acid, leuconic acid, k produced: 



C^H-0* 


+ 





+ 


3H*0 


^ 


c*n»o». 


CrocoQlc 












Leuroaic 


acJd. 












aclJ, 



The crocon a t e 8, C*M*0*, are yellow (hence the name of the acid). Many of them 
are anhydroiis (Will). They decompose below a red be^t, with glowing and B|)arklinfr, 
giving off carbonic oxide and carbonic anhydride, and leaving a mLxturo of t'liareoul 
and metallic oxide, carbonate or metul They withstand tlje action of air and light, 
evoQ th^ir nqueoua solutions not being altered by exposure io the air. The crt>conat*a 
of the a! kstli- metals and some othera are soluble m wat^ir; they iill dissolve with decom' 
position in nitric acid {vid, 6up.) Some of the croeonates of the heavy metals are 
soluble in alcohol and ethcK (lie Her.) 

Croconatc o/ Aluminium. — Yellow cryitala easily soluble in water and alcohol. 
(Heller.) 

Croconate of Ammonium. — ^Reddiab-yellow needloa soluble in water and aleohob 
(Heller.) 

Croconate^ of j^n^imonj^.^-Croconate of potassium added to a solution of tri- 
chloride of antimony in hydrochloric acid forms a lemon-yellow preeipitjite^ soluble in 
excess of chloride of antimony, ( G m e 1 i n. } 

Vroconale of Barium, 2C*Ba'0* + 3H'0 (Will),— Yellow pulTomlent preeipi- 
taU\ insoluble in water and in alcohol (G- m e li n). Does not give off its water al 20tl^C. 
(WilL) 

Croeonate of Bidmui L — lyemon-yellow precipitate soluble in exoess of nitrate 
of bierauth (Qmelin), Containa 5368 per cent. Ui'O". (Heller.) 

Croconate of Oatfmiwm,— Yellow pulveiralent precipitate, somewlmt soluble in 
water an d alcohol (Heller.) 

Croconate of Calcittm, — Lemon-yeUow crystals sparingly soluble in water and 
alcohol (Qnielin). They contain C*Ca"0* + 3H'0j and give off their wat*r com- 
pk'tdy at 160°C. (Will) 

Croconate of Cobait, — The potassium- salt mixed with an aqneooa cobalt-salt 
yields, after a few hours, dark-brown tmnsparent crystals, with beautiful violet rwllex ; 
soluble in water and alcohoL (Heller.) 

Croconate of Copper, C*Cu'0* + SH'O, is deposited in prismatic crystals on 
mixing the hot solutions of croconate of potassium and cupric chloride. The crvstals 
belong to the trimetric system. Dominant form, ooP, with the faces ae P oo. ludi- 
nation of caoP: ooP in the brachy diagonal principal section = 10^'^, Cleavage 
parallel to ooP. The crystals have a fine deep blue colour by reflected light, and 
appear orange- colouretl by tmnsmittcd light They give off !3-8 per cent, (« 2 at.) 
watOT at 100^ C, the remaining atom not being given off till the salt is heated to a 
temperatuire at whicli it undergoes complete decomposition, giving off carbonic oxide and 
carbonic anhydride, yieldio^^ an add diistillate* the hitter portions of which form a block 
precipitate with oitmte of silver, and leaving a residue of copper and charcoaL Tho 
salt, heated in the air to a temperature below redness, bums with a glimmering light 
and slight sparkling, leaving &rst a red powder of metallic copper, afterwania CDprie 
oxide. Fuming nitnc acid sets it on fi^ro with vivid sparkling, 

Croconate of copper dissolves very sparingly in cold water, rather more in boiling 
water, forming an acid solution, which forms ^vitli potash a blue precipitate soluble in 
excess of the ulkLili. Ammonta produces a similar reaction, and likewise dissolves the 
crystals. The aqueous solution forms but a slight deposit of copper upon iron, unless 
hydrochloric acid is also present. (Omelin.) 

Oroeonates of /ro«.— Croconate of potassium forms with a^iueous /<rm<; chloride 
a clear black mixture, which in thin layers exhibits a garnet -red colour (Qmelin): 
it diL'posits indistinct^ very dnrk-coloured ciyst^ils, soluble in wateir and Hlcohol 
(Heller). The potassium -salt^ added to /arrows sulphite forms a dark yellowish 



CROCOX AKTHIN ^ CRONSTEDTITE. 



Ill 



liquid, wHcli afterwafda deposits brown fljOcea, cbanging, aft«r some houra, to dork 
brown czystaK blue hj reflected Light ; tbaj resemble the copper-salt m form^ and ure 
soluble in water and i^cohoi (Uelltisr.) 

Croconafrd/Zr^arf.—CWO» + 2H'0 (Will), is obtained bypourinpf, firef acetic 
acid, then a hot dilate solation of acetate of l<*aa» into a solution of tirocotiiit« of po- 
tassium. It ifi & micaceonSf golden -jeUow prmpltate, which gircs off it« wat^ at 
180O0. O^^ilL) 

Croconate of Mag nesiu m, — DaA brown prisms. (Heller.) 

Croeonate cf Mangantae.^-Bj emp^riLtiRg the acid with mangauDXis aoetat^ of 
liATing the potassinm-aalt for somo time in contact with manganons inilph&t«^ dingy 
y^Uow eryatiua are obtained, having a faint blue reflex. (Heller.) 

Croeiynattof Mcrcurj/. — Tb© potassium-salt added either to mercuric or mcr- 
ennms nitrate, forms a yellow preeipitat4?. 

Croconaie of NickrL — By evaporating croconie acid with sn1phat« of nickel, 
light brown grains are obtaincni, fioluble in water and alcoliol (Hellt^r.) 

CroconaUM of Potassium, a. Neutral ^ C*K=0* + 2H=0. — Prepared by cjiii- 
tic»UBlj diasolTing in wateir the black mass abtained as ah accessory product in the 
prmration of potaw»qni, ^-filtering, = concent mting the filtrate over the watcr-Tmth, 
and lenTiDg it to crystallise, — pressing the yellow n&edlea thus obtained, — and re- 
frystalliiong from hot water (Gmelin). Crystaflises in slender necKiles or prisms 
of an orange yellow colour, which effloresce and give off their water at a temj>eratiiro 
ooosidenibly below 100** C^ or when treated with oil of vitriol, and become U^mon- 
vellow. At a high tem|^eraturo the salt earbonisee. Nitric acid and chlorine 
decolorise it, and ooDTort it into leuconate of potassLuni (p. 108). It is moderately 
aolnble in wat«(r« en>«cially in hot water ; insoluble in absolute alcohol. The aqui^tia 
solution reduces chJoride ofgoid when heat«d with it; with mercuric chloride it forms, 
aft49 a while, a white precipitate, probably consisting of calomel. 

3. Jcid tait, (7HK0*C»HM)* 4- 2H'0.— Obtained by adding to a solution of tho 
Dcutiml salt, a quantity of ealphnric acid, not sufficient to defompose it pomplctely. 
FofTDS prisms more deeply coloured than the neutral salt, and having an acid ivaction* 
(Omelin.) 

CroeonaU of SH^er^ CAgK>*, is precipi tated in aurora-red fiakcs, insoluble in water* 

Croe&naie of Sodium^ obtained by jieutrdli sing the acid with cartfonate of kh 
dium, forms rhomboTdoI prisms less deeply coloured than the potassium -salt, and 
containing water of crystallisation, Teiy sokblo in water, sparinglj in alcohoL 
(Heller,) 

Croeonats of Tin, — The potassium-salt, added to a solution of stanmm chlondo 
throws down a large quantity of an orange-yellow powder (Gmelin) ; it decomposes, 
with Tiolence when bested, and is sparingly soluble in water (H el ier). Stannio 
cMurids is not precipitated bj croconate of potassium. 

Croeonateof Uranium, — ^Th© hjacjnth*r©d miittire of croconic acid or croco- 
nsie of poUannm with uranic nitrate yields, by spontaneous evaporation, yellowish- 
rvd, transparent crystals, easily soluble in watii^r and in aloohoL (Heller.) 

Croconate of Zmc, — Cr}'stalline grains soluble in wat-erond alcohoL 

Cf neonate of 2ir<?onii*m, — Yellow crystals soluble in water and alcohol. 
(Heller) 

OSOCOXAarTaiar. A peeab'ar yellow colouring matter, said to exist pure in the 
iovers of CrocwluUns, mixed with other substances m the stigmata of Crocits sativvs 
tad (Mi»U9 multifidvs, and in other plants. It is a golden-yellow amorphous body, 
of eonsideTable colouring power, easily soluble in water and alcohol, bat insoluble in 
«ther. It is not altered either by aci(£a or by bases, — a character whicli distinguish o?! 
il from other yellow colouring matters, such as xunthin* &c* ; forma yellow Inken wit li 
•eretml raetolUe oxides, and may be flxed on tiKsucs. (Filhol, J. Pbarm. [S] xlviii.) 

CBOCnrS* A term applied by the older chemists to many metalic coinpoiind?; 
tiling oaQ^ffiilphide of antimony (i. 328) was called Crocm Antimtmii^ or Crocus mt* 
UMormn; sesqmoxide of iron. Crocus Martis and Crocus Mariis apcritivus : cuprous 
oxide, Crocus Fir«rrw, &c. 

CMOCtfB BATXWS. See Sajtbok. 

cmowSTBDTZTS. Chloromelam. — Ahydratcd ferrous silicate, containing also 
small quxintitjefi of niagnesia and manganese, found in a Tcin of silver ore at Prxibcam 
in Bohemia, acconnpinyiiig pifTite, siderito, calcitc, and limonite ; also at Wheal 
MAiMJlin iQ Com wall, with pjrite and sidcrite. It crystal! ine^a in the hexngonal system, 
Ibnntng itx-iididpirismS) with the busic terminal face^ generalty in divei^ing gToa£« ; alao 



112 



CROSS-STONE— CROTONIC ACID. 



Tpnifonti and amorphous. Cleavage basal, Tery distinct* Colour raven-blat-k Streak 
dark-groeti. Opaque, with strong vitreoas lustre. Rather brittle ; thin laminae, 
BOmetrhat flexible Specific gruvity = 3-3 to 34. Hardue^^a = 2"5. Before tho 
blowpipe it BwelLi up a Ktde, and mf^lta on the edges to a bhickiah-fp-ej ma^etic 
ilag. With bof«x and phosphoms-sHlt it gives the reactioti^ of iron, silica, and man- 
ganeao ; witli aoda, that of miiugaiiieae. It givea off water when heated in a t«st-tube, 
X)eeompo*k!id bj hydrochloric or Bulpburie acid, fonmng a j^j of ailica. 
Analysis, hy Kobell (Schw. J. Ixii. 1&»): 

SiO" Pe'O Fe^O" Mg=0 Mn'O H'O 

22"46 27 IS 35*35 2'BB 5*08 lO'TO^loaiJi, 

agreeing approKimatelj with the formula 3(2Fe»0,SiO*>2(r©«Ol3HK>), or 3Fe*8iO« 
+ 4(Fe^)"'H-0'. 

CROSS-STOIVS or C&UCXTB. Sjn. with CmJLSTOi.iTE (i. 868), 

CROTOia* OIl«* Oleum crokmis. — A fatty oil exist m|?, to the amount of about 50 
per cent, in the sf^eda of Croton Tiglium, a plant of tb«> Eitphorbiaceous order. It ia 
usually obtained by strongly prcaamg the bruisod Bceds between hot platea, — aoine* 
time-n by digestion with alcohol or sulphide of carbon. 

The properties of croton oil differ to a certjiin eitcnt aecording to the mode of pre- 
pftration. The oil obtained by pressure has a more or leas yellow or l>rown colour, 
and tt peculiar rancid odour ; its ta»to is mild at first, but afterwards burning. It ia 
somewnat viscid, especially when old, and deposits more or less of a dirty white body. 
It m a powerful drastic pur^tive, and irritates and reddens the skin. *fhe latter pr^ 
pcrty i« due to a peculiar oil? body, called croton ol^ C?*H**0* The purgative action 
wa« formerly ascribed to a volatile add of the oleic series, crotonie acid ; but subw*- 
queot investigations havo abown that this is not the ca*^ ; the exact nature of tho 
piugative principle is not known. According to Mayer (N. Jabrb» pr. Pharm. x 
318), a volatile, highly irritatiag substancCj which afiects the lining membmneJS of 
the noae and mouth, ie evolved during the pressing of croton seed* between wami 
plates ; this sitbstiLnoe also remains to be investigated, 

Brandes, who flnt examined croton oiJ, auppo«ed that it contained a ^moll (quantity 
of an alkaloid, to which he gave the name crotonine; he obtained it by digeating 
tlie alcoholic citract of croton seeda with water and magnesia. According to Weppen, 
however, this supposed alkaloid is notiiing bilt a ntagnesia-fioap of croton oiL 

The mo«t fXAot investigation of croton oil has h&m made by Th. Scblippe (Ann. 
Cti. Phamj* cv» 1). To obtnin the oil, the seeda were first pressed between warm 
phites, and the remain trig cake, after being comminuted, was exhauiited with alcohol 
of 85 per cent, in ti displacement apparatus^ so arranged that the aJcfiliol which ran 
off could be distillcjil hack again. Aller this process had been repeated four times, the 
receiver contsine*! two layers of liquid, tho lower of which was oQy,, and contained 
14 pta, oil to 1 pt. alcohol, the upper mobile, containing 23 ptA tdcohol to 1 pt, 
oil. The leaiduiil mass, still saturated with alcohr»l, was preasou, and yielded a con- 
sidenible quantity of oil surmounted bj a layer of alcohol. From this and the pre- 
ceding portions the alcohol was distilled oSl In this manner four portions of oil were 
obtaiuea. (1.) The portion obtained by warm pressure; (2.) That which waa dis- 
placed and dissolved by the alcohol j (3.) That diapkced by the akobol but not dis- 
iMjlved, forming the lower layer above mentioned ; (4») The portion expirfifised from thfl 
residue. Of these the second exerted the strongest irritating action on the akin ; this 
action wa« much weaker in the third, and weakest in the first and fourth. 

Croton-oil obtained by pressure was found to contain stearic^, palmitic, myrisb'c, and 
lauric acids^ two acids of the oleic series, whose formulae lay between C"H**0' and 
C'*H'"0', — also crotonie and angelic acids, together with glycerin and other stib- 
Btoncesi. 

Tho alcoholic extract of cpotoU'seeds, diluted with water and evaporated to remove 
the alcohol, became turbid on cooluig, and deposited a dirty yellow crystalline lK»dv, 
which has not been further examined* but is perhaps the pnigative principle of the 
seeds. This body is decomposed during the saponiAcatioia of croton oil, and yields 
a peculiar black rojfin {vid. mip.) 

cmaTONZG ^CTD^ C*H«0' - C*H*O.H.O, or C"^0*, (Pelletier and Ca* 

ventou, J. Pharm. iv. 289. — ^Caventou, ibid. xi. llO.^Buchnor, Repert Pharm. 
xix, 185.— Schlippe, Ann* Ch* Pharm, cv. 1.) — This acid, which l>efongB t^ tlie 
oleic series, C*H**^-*0', and occupies tbe intermediate pluee between acrylic actd 
C'H*0^ and angelic add, Cf*H'0', is obtained by the auponiftmtion of croton oil. The 
oil extracted by pressure is saponified with soda-ley ; the alkaline liquid is treated 
with common p^dt^ which »€»panit4?8 a soap containing palmitiite, Rtoarate, m3rristate, 
and laumte of ecKUumi leaving czotonate fwd migektc in solution ] this soap is 




CROTONOL — CRUSTACEA, 1 13 

srith brine ; and the mother-liquor, together with the washings, is supersaturated with 
tartaric acid. It then becomes colourless and deposits yellow flocks, — a product of 
the decomposition of the supposed purgative principle mentioned in the last article, — 
which cake together to a black resm. The filtered liquid is then distilled ; the dis- 
tillate, containing crotonic, angelic, and hydrochloric acid, is neutralised with baryta, 
and eyaporated to dr^ess ; and the residue is again distilled with dilute tartaric acid. 
Crotonic acid then distils over fiirst, together with water, and afterwards angelic acid 
crystallises in the neck of the retort. The saturation of the liquid distiUate with 
baryta, and the decomposition by tartaric acid, are repeated till the distillate no 
longer contains hydrochloric acid ; the liquid is then finally neutralised with baryta ; 
the excess of baryta removed by carbonic acid ; the filtrate eyaporated to dryness ; 
and the residue decom|)osed by heating it with strong phosphoric acid. As the liquid 
cools, the crotonic acid rises to the surface, and may be separated by means of a 
pipette. 

Crotonic acid is a colourless, oily liquid, haying a somewhat pungent odour and 
an add taste. It dissolves with moderate facility in pure water, but is insoluble in 
saline water. When carefully heated with hydrate of potasaium, it gives off hydrogen, 
and forms acetate of potassium : 

C*H«0» + 2KH0 « 2C«H«K0* + m 

The crotonate8 are inodorous. The potassium-salt forms rhomboidal prisms, 
permanent in the air, sparingly soluble in alcohol of specific gravity 0*85. The barium^ 
salt is yerr soluble in water and in alcohol, and separates by concentration in nacreous 
crystals, the powder of which excites powerful irritation in the throat. The magne- 
sium-salt is granular and sparingly soluble in water. 

Crotonate of ammonium forms a cream-coloured precipitate with ferrous sulphate; 
white with silver and lead salts ; bluish-white with salts of copper. It does not pre- 
cipitate ferric sulphate or chloride of mercury. 

. CSOTOVOL C»H"0«. (Th. Schlippe,Ann.Ch.Pharm.cv.l.) — Containedin 
croton oiL To prepare it, the oil is shaken up with a quantity of alcoholic soda sufi- 
cient to form a milk ; the mixture is gently heated for some hours ; water or brine is 
added ; and the oily layer which then rises to the surface, is completely removed by 
repeated filtration through wet filters. On mixing the filtrate with water and hydro- 
chloric acid, another oil separates ou^ which is dissolved in cold alcohol, digested witii 
hydrate of lead, till its acid reaction is neutralised (whereby a fiocculent precipitate is 
formed which aifterwards coagulates into a greasy mass), then mixed with a little soda 
and a laige quantity of water. The milky Uquia thereby produced becomes clear after 
a while and deposits an oil, which is to be washed with water, then dissolved in ether, 
and the ethereal solution again washed with water, and evaporated in vacuo. It then 
leaves crotonol amounting to 4 per cent of the oil. 

Crotonol forms a colourless or faintly yellow viscid mass of the consistence of tur- 
pentine. It has a faint peculiar odour, and is the part of croton-oil which irritates 
the skin, not the pui^a^ative principle. 

It cannot be distilled without decomposition, even in vacuo or in a stream of 
carbonic acid gas. When distilled with water, either pure or containing sulphuric 
arid, it yields first a colourless, then a black oil, which cannot be distilled at 200° 
even in yacuo, and leaves a black resin which forms with alcohol a turbid solution 
prccipitable by acetate of lead. A solution of crotonol in absolute alcohol does not 
form crystals with ammonia. Crotonol does not combine with acid sulphite of sodium. 
With melting sodium it gives off gas with violence, then becomes thicker and resinous. 
By boiling with caustic potash or soda, it forms a brown resin which no longer reddens 
the skin. The alcoholic solution of crotonol does not precipitate metallic salts. 

fSWLlOfUWZ OTMBm Toloucina oil. — A fatty oil obtained from the seeds of Carapa 
Tcloucina, a tree twenty feet high, growing on the Gold Coast. The seeds are first dried 
and smoked, then bruised, boil^ with water, and the oil which separates is collected. 
The oil has a bitter taste, apparently due to the presence of a foreign basic substance, 
and a repulsive odour ; it dissolves completely in ether, but is separated by alcohol 
into two parts, the solid portion, together with the basic substance, dissolving, while a 
liquid oil remains undissolved. Croupi oil is used by the natives of the West Coast 
of Africa for burning, and as a remedy against intestinal worms. (Handw. d. Chem. 
2- Aufl. ii. [3] 231.) 

cmO'WW O&ASS. SeeGLAsa 



See Staubolitb. 
Syn. of Chiastolitb (i. 868). 

The shells of cmstaoea contain oi^ganic and inorganic matter in 
VouIL I 



114 



CRTOLITE — CR YSTALLl S ATION, 



nenrljr equal qoantities, the moi^iinic portion consiBtiDg maialj of carbonate of cdcium 



with a fiiimller qiiantity of phosphate. 
in the shi*ll 



Fre my (Atm. CL Phya, [3] xliii. 47) found 





Cn^PO*, 


c»«co». 


Orgaaic matler. 


Of the Bca-crab * 


. 6'7 


490 


44-3 


Of the land-crab . 


. fi'7 


668 


36-5 



The organic portion oonaijtj mainly of chitJn (i. 874.) 

CRTCI£ITS. Natiye fluoride of sodium and alumininin, 3NaF.Al^F*. Found in 
larp»? qurmtily &t ETiqflok. in thfl Arksut-fjordi in Wcat Greenland, where it forma a 
bod 80 feet tkick and 300 feet long ; also, with chioHtG, Uthi&-mica and Huor spar, at 
Mi ask, in the Ural. Crystallise* in tlio dimetric system. Specific gravity = 2-& — 
3'08. Hardness = 2 5. Colourless niid traii«pareivt when pure. At the surface of 
the bed just mttfitionedt the mineral is white, Imt below tJie surface it exhibits a eon* 
tinualiy darker coloan and at last almost blHck: thd eolonr is, howorer, deatroyetl by a 
moderate heat. Crj'olite melts below a red heat and forms fiui opaqnc glasa on cooling. 
It is very slightly soluble hi water. It ia used for tho extraction of alnrainium, and 
also for the preparation of eaiistit! soda for soap-hoiling. (See ALuitrnniM, i, 167.) 

CTL Ti If TXnZlf S« C'*n"N. An organic baae contained in that portion of the 
bases from coal-tar {a, t\) which pos»csaes the highest boiling point (above 274*^ C). 
It has not been obtained piLpe, its composition havinig been determined only by the 
analvsis of the pl>itiniim-salt. which crystallises in yellow needlt:^. It is homologons with 
chin'otine, C^H'N, aod lepidine, C"'H''N. (C. Gr. WilHama, Chem. Gaz. 1866, Hm.) 

CR17TOX»X]f^ An organic liquid, found togethi-r with brewstolin (L 663) in 
cavities of topaz, chrysolieryl, quarta-crystals from Qm-bi'^c, ntid amethyst from Siberia. 
The two liquids sometimes occnT in the name cavities, but they are not miscible. 
Cryptolin, when exposed to tho air. flpcetlily hardens into a yellawishj trausporont^ 
resinous body, not volutilisable by heat, or soluble in alcohol or in water^ but dissolinng 
rapidly and with effervescence in sidphurie acid. Nitric and hydrochloric acid also 
dissolve it. Indci of refraction nearly tho same as that of water. (Dana^ ii, 47 1-) 

C&^FTO^ITB (from ifpuwroi, concealed). Native phosphate of cerium^ CeTO*, 
discovered by Wohler (Ana. Ch, Phann. Mi. 268) in the rose-coloured apatite of 
Arendal in Norway, from which it is separated by dissolving the apatite m nitric add, 
the cryptolite then i^maining usdiaBolvftd, in Tefy jmall beKagonoI etystaU. (See 
Phosfkatbs.) 

CMYBTMS^IW, or Ghbtdin. An albuminona snb«tance, contatned in the crys- 
talline lenH of the eye, and supposed by Borzelius to be identical with the albimiiiiouA 
constituent of the blood-eorpusclea, (See QLOBULm.) 

CftvfiT.A.XiXiXirM* An old uame for aniline or phenylaminc. 

CXTSTJL%XilSA.*ftOir. A crystal is a solid body, bounded by nlane mirfaces, 
diflfjT^ed ttccoriling to a regular law of symmetry, the form thus produced being es;sen< 
tially related to the eomposiitiou and properties of the body* so that tho minutest par- 
ticles into which tho body can be mechamcally divided exhibit either the some form, or 
one related to it by determinate laws. This easentiid connection between form and 
composition distinguishea a crystal from a regular form artificially produced^ aa by 
carving or morlelling. All crystnLi cleave in certain directions more easily than in 
others, and all, C3icH>f ing thoao which belong to the regular system (see Cktstallo* 
gbAfht), refract Hglit doubly. 

To enable a body to assume tlie crystdline state^ its partidea moat po«aeaa a certain 
fk'eedoiii of motion.*, henee, the fluid state ia for the most part, an easential preliminary 
to crystalliwation. Sometimes, indeed, an amorphous solid — tbat in to say, one whicti 
has no definite stmrtnre, either crystalline or organised — pauses spontaneoturlv into 
the crystalline state without prcviima liquefaction. Thin w the ease with plastic sulplmr, 
vitreous arsenious acid, and barley-sugar, which gradually change from tniOfpjiront 
amorphous solids to opaque aggregates of minute crystals. But generally speaking it 
ia in the passage of s body from the liquid or gaseous to the solid st^te that the regular 
and symmetrical arrangement of the molecules takes place, which constitutcit crj-stalH- 
fation. The Tapouraof many stibstancos, when they come in contJict with cold surfaces 
pass at once to tho state of crystalline solids, c. (f. sulphur, iodine, Itemsoic ocid, arse- 
nious: acid, camphor, &c. It is, however, in the trantition from the liquid to the 
solid state that crystallisation most frequently takes place. If the body has been 
brought into the liquid state by the action of heat alon*:-, it may l^e made to erj^»t.alli''e 
by cooling, e.g. bismuth,, aulphur. To obtain deflnite crystals in this manner, the 
liquid ma-Hs is allowed to cool only till a certain portion near the surface and in contact 
with the sides of the vessel haa become solid, a hole being then pierced in tho cnist* 




CETST ALLI S ATION, 



115 



And the Teseel inTerterl, so that tbe portion whioli a till remains liqaid may nm out 
Wi. 690). A solid body dissolved to sattiration in u hot liquid may also th? made to rrya- 
iailifi^ by cooMjigj e. q. tulpbur from solution in sulphide of carbon ; nitre or aJum from 
solution in water. The crj-»tatlisation of a solid frim solution may likewise be cftkjted 
by ramoTing the solvent, either by eraporation, or by adding another substance with 
which the eolv^nt ha« a greater t^ndeney to unit^ than with the aubstance previously 
dissolTed in it ; in this manner, cblonde of sodium cTystalli»e« from its iqnsotiii solution 
on addition of chloride of calcium ; nitre from ita agueoits solution on addition of 
alcohol; iodine from solution in hydrtodic acid on the introduction of a smaU quantity 
of chlorine. 

The more slowly th© liquefied body is brought back to the solid stat*, and the more 
the b*quid is kept at rest^ the smaller is the number and the greater the size and re- 
gularity of the GrystaJs ; but if the solvent be cooled or separated quickly, the cjystals 
are niuneroas but ^mail and ill defined. In the former caaep the particles of the eolidi- 
fring body have time to unite themselves regularly with those whieb tieparute first from 
tile fluid and form nnclei of crystalliaation ; if^ on the contrary, the crystallisation t4ikes 
pkAoe rapidlyi a great number of particles solidlQr at the same time^ each formin|]; a 
anelsQS to wMcfa oth^ portions may attach thKosetree, and thna we obtain a number 
of cmtals irrei^alArly formed and interlacing each other in all directions. In tlus 
consists the diflTerence between siigar-caudy and loaf-sugar; similarly, all ([i^aiiular 
and Bbrous bodies, such as tufn and iSbrous gypsum, must be regarded as coUections 
of imperfectly formed erystal^H, To obtain crystals as large and regular as po8;sible, 
Leblane recommenda (X Phys. Iv. 300) to allow a solution not quite saturated to cool 
alowlj, so that none but distinct crystals may be formed, then to pick out the best 
formed of these and lay them, separate from one luiother, in a solntioa of the same 
mJc, which by gentle wanning m contact with tlie salt has been made to hold in 
solution a quantity of it just a little greater than tJiat which it can contain at the 
ordinary temperature^ so that il may deposit this excess on the crystals laid in it. 
This troatment is repeated till the crystals have obtained the desired magnitude, care 
bezDK taken to turn them fre<5uently, because the surfaces resting on the bottom are 
in a iMi fiiTOurable position tlan the others for taking up fresh particles. The trouble 
of repeatedly prepanns a alightly snpeFsatnrated soindou may be saved by suspending 
in tae upper part of the liqmd a quantity of the salt contained in a bag of muslin 
or in a fiinneL Irrcignlarly developed crystais may also he brought to regular shape by 
covering the fully oovelopBd sorfacee with wax, so that only the laces wliich require 
further development may come in contact with the solution. 

The formation of crystals takes place most readily in contact with bodies which 
ahetract beat from, the liquid, or to which the crystals can adhere. Hence they 
Ibim OB the mir&oe of the liquid, in so far as evaporation and eooling by the in- 
Uneoee of the aii; or adhesion of the air to the crj'stals, can give rise to their pro- 
dnetton; also on the bottoms and sides of the containing vesspls, and ou solid bodiea 
taUDArsedin the liquid. For tlm most part, crj'Stils deposit tJiemselves more easily on 
wood and string than on porcelain, glass, and metal ; more easily on porcelain than on 
giMB, and generally more easUy on rough than on smooth surfaees, because the former 
tw e ecu t a greater number of points of adheaion. When a glass tube containing a crystal- 
UMble liquid is scratched with a glass rod, the crystaJd deposit themselves in preference 
on the seratchet. CTiystallisation is also especially facdifated by introducing into the 
bqoid a crystal of the substances previously formed. A solution saturated at a high 
temperature may, under certain circumstances, l>e cooled down several degrees without 
depositing crystals ; but the introduction of a crystal of the substance, causes the whole 
to solidify instantly in a crystalline mass. This phenomenon is easily exhibited with 
Glanbei^e salt (See SoimoNS, SuFSBSATtraATED.) In like manner, the introduction 
of a oystal of nitre into a solution of nitre and Glauber's salt, prepared hot and sub- 
luently cooled, causes the nitie to sepflrate alone; a ciystal of Glauber's salt removes 
[y the Glauber's salt ; wheress, if the solution Ijc left to itself, both salts crystallise 
it together, the crystals int-erlacing each other. (Lo witi^) 

When a solution evaporates below its boiling-pr^int, the first crystals are usually 

posited on the sides of the vessel at the uppermost surface of the liquid : another 

rtion of the liquid often rises through these, and yields by evaporation new cr^'stalst 

hich ultimately m;ike their way over the edge of the vessel This is efflorescence. 

rben crystals form at the bottom of a liquid, a current is prr>duced, because the in- 

dividnal ctystals take, from that part of the solution with which they are immediately 

in o>ntact, as much of the salt as is possible under the existing circumstanct^s ; eonse- 

qMHtlj this part of the liquid becomes lighter and rises to the surface, its place being 

WBfjjiTd by a more saturated portion of the liquid. 

^Vhan a body crystallises from solution in a liquid, and the lattesr is not completely 

by eTaporation, there remains a portion cjille*! the mother-liquor (Etru 

1 2 





A 



JW 



CRYSTALLOGRiVPHY. 



mirttf Muiteirtauge). This Hqaid holds in Bolution a« mudi of thp crystallising 
body 80 m consistent with it^ quanfity jiud temperature* It oft<*u happens, especially 
when cryataUisation ppoc€«ls rapidly, and the crj^atidHne laminjp in the at't of nuiting 
IfAve Atnall apaoes lietwecn them^, that gmall and (even with regard to the aame sub- 
stance) vwy TAriable quantities of the mother-liquid remain enclos'?d in the cry^ftal- 
line mass, fontiiuf^ tbo Water of Decrepitation. Crystala which contain liqnidH 
thus enclosed, and do not melt below the boiling*point of the mother-liquid, exhibit, 
wh^^n heatod, the phenomena of Decrepitation,the vapour given off from the mother- 
liqnid bursting the ciyHtalHne miunjwith violence. Thia water of decrepitiitjon, which, 
OS an aecidtrntal mechiinieal admixture, has no influence on the form of the crystal, m 
altopether difFtrent from the chemically-coinbiBed water which certaiQ cnrstalB contain 
in ili^6iiite pn^poi'tion, and whieh is esseattal to their ci^etalline form. Uommon salt, 
crys<tiil]i Med by slow evaporation from an aqueous Bolntioo does not decrepitate?; bnt 
when rrystalliBed by rapid boiling of the liquid, it decrepitates riol^tly. Many forms 
of <*alcspar decrepitate, othem do not. 

If a solution, in addition to the cryntaliiMing: substance, likewise contains others 
which are less easily crystallisable, the latter \n'll remain in the mother-liquid after 
the separation of the greater part of the fonner. Thiiii circumstance fuTni»hp« a 
method of purifying eafiily crystallisLableeubshinccs by repealed solution, crystaUisation, 
pouring oflTof the mother-liquid, washing with small quantities of tho coldHolrent, and 
prewing bc^twcen blotting-paper. In this method of purification, the formation of lar^ 
orystala by slow cooling or evaporation is usually preferred, beeauae they present fewer 
surfaces, and are therefore more euaily freed by washing from the adhering mother- 
liquid. Sometimea, on the contrary, as is the French method of purifying saltpetre, 
the smallest possible crystals arc formed by c^nataot stirring and rapid cooling of the 
hot solution, because large crj'stjila of this salt contain a greater quantity of mechani- 
cally includod mother-liquor, which cannot be removed by wiishiiig. 

It has already been stated that the crystalline form of a body bears an essential 
relation to its nature and composition. Accordingly we find that every substance 
crystallisett either in on« single form or in a nnmber of forms related to each otber by 
simple laws and deriTabl© one from the other ; in other worda belonging to the same 
crystalline system (see CRYaTAi.ix>OR.iPn[T). Many bodies, however, both simple and 
compound, crystallise in two or more forms belonging to different crystalline syetems, 
and not derivable one from the other- such bodies are said to be dimorphoua, tri- 
m o r p h o u 8, or rc n erally polymorphous. ( See Di m oupuism. ) 

On the other hand, different sulwtivnceiH often crystallLse in forms either identical or 
pithibiting only small differences in the inclinationa of 4he corresponding plane?;. 
When the formn are exactly similar, the Bubstanccs are said to be isomorpbous, 
when small difFerences in the angles exist, they are called homceotnorphou«. 
I^omorphous or homceomorphous compounds exhibit jwrfect simihirity of chemical 
composition : thus, the alum.^, which crystallise in regular octahedrons and allied forms 

are.all eomposetl according to the general fonnula /my^f 2S0* +12 aq., where M de- 

note.4 a raonatomie metal, like potassium, and R a scsquiatomic metal, like aluminium ; 
the magnesian double sidphates, which crystallise homoeomorphously in the monoclinic 
evKtem, are all composed analogously to sulphate of mogue^iura and potiWiiium 
(K3f g:)SO* + 3 nq. Isomorphous salts are capable of eiystallking together in any pro- 
portion ; in other words, the isomorphotis elements which enter into them are capable of 

replaciugoneanotherin any proportion; thus^ common alum >..(.,„ f2S0* + 12 aq* and 
{ 230^ -f 12 aq.^ c&n dyatallijie together in all proportions \ hence it 



iron^alum, 



K 

CFe*)' J 
is diffit^ult to purify common alum from iron by crystalliaatiou, 



(See IsoMORi>m5M.) 



CSTSTiiX^OOSAPair is the science which treats of the external forms of 
eryat&]«* and of the laws of symmetry according to which their faces are disposed. 

Ctyatiils iire bounded by plane faces. The straight line in which two contiguous 
faces intersect is called an edge; the point in which three or more faces' intersect is 
called an angle, solid angle, or summit of the crystaJ* 

01iiill»r And DfaaliQllttr Sotmdftrles* Similar faces of a crystal are 
those which resemble eiteh other in form and in relative position j di.«isimilHr, those 
which differ in either rewpect. Similar edges are those which are formed by 
similitrly situated faces meeting at equal angles. Similar angles or summits are 
those whicli are formed by the concurrence of similar facca and edges; angles are silso dis- 
tingtiiahed as three-faced, four-faced, &c., according to the number of faces by which 
they are formed. The regular octahedron {fy, 149), and the cuh<^ {Juf. 160), have all 
their faces, edges and angles sitnilar; the rhombiedoclecahedron {fig, 151) haa all its fneea 




CBYSTALLOGRAPHY. 



117 



Fig, H9. 



Fig, 150. 




^ — I — r^ 

j <»Oo. • 

,'__4 .^.-y 

I ^ 

I 

i I 



ind edges similar ; but its solid angles are of two kinds, viz. eight 3-faced and six 
4-£Dced angles. The square prism with pyramidal summits {fig, 152) has dissimilar 



Fig. 151. 



Fig, 152. 





-P 



•p; 



&ces. triangular and recta n gul ar ; dissimilar edges, \vl. 1, those formed by the inter- 
Mvtion of two triangular faices ; 2, those formed by two rectangular faces ; and 3, 
tbiise form<Ki by a tria n gular and a rectangular face ; and diK.siniilar angles or sum- 
mits, yiz. two at the extremities of the vertical axis, formed by the concurrence of 
four similar triangular faces ; and eight others, also four-faceil, but formed by the inter- 
section of dissimilar faces and edges. Angles are also spokon of as equal- or un- 
equal-edged, according as the edges which meet in thmi are similar or dissimilar. 
An anequal>edged angle may ahto be symmetrical or unsymmetrical, according 
a?* the dissimilar edges which form it follow one another in regular order or not. The 
f >ur-vdged angles of the double six-sideil pyramid {fig. 153) are s^-mmetrical, but 
thoso of the six-sided prism with pyramidal summits {fig. 151) are unsymmetricai. 




Ua^to MiA Ctomptos twmm (OomMnatlotis^ Simple forms are those 
vhiefa contain only similar fiices, §,g, the regular octahedron, cube, and rhombic do- 
deadisdroii(/h^. 149, 150, 161). Complex forms, or combinations, are those in 



118 



CRYSTALLOGRAPIIY. 



wkich disflimilar feofii oeenr (f.o. figs. 162, 154). A combination is made ap of tho«© 
aimple forms which would rtasuft from the eitenaion of one set of similar fki* till tho 
Others disappeArj thus {fi^g, 165) is ft combination of the octahedron O, and tho 
rhombif.* doaecahedroB »0- If we stippoeo the 0-facea to be extended till they meet, 
the OB 0-faceft will disappear and the oefahedroii {Jiif. 149) will reetdt; con verily tho 
extension of tho faces ccD to tho obliteration of the others produc^i'S the dodecahednin 

The relation of a complex form to the simple forms of which it is made tip may 
ahso be represented a& follows : — Siipppose two or more simple forms, a» the cube and 
octahedron (j^*. 166, 157), to be constructed round a common centre, and of such 





dimenBionfi, that certain pirta of each oimple form »hall project beyond the limits of 
the other, then the combination (represented by tbe shmled portion of the flpires) 
occupies tbsit portion of space which lb common to both the simple forms ; tho^e por- 
tions of each bein|i eiclnde«l, wbich project bt^yond the space enclosed by the other. 

lu any combination of simple forms, tho one whose faces are most developed, and 
consequently determine the general aspect of the crystal m eallod the dominant 
form; thus in the combination alcove Tepresented, the dominant form itfj^. 16G is the 
octahedron and infy. 167 the cube. The other (subordinate or eecondary) faees 
are described aeoording to the munner in whieh they aro related to the dominant fac«8. 

The secondary faces of a crystal may repkice either the edges or the angles of the 
dominant form. If an edge i» replaced by a face which mokes equal angles with tho two 
coutiguoiii* facesof the ciy^tal^ it i<* said to be sym metric ally or perpendicularly 
truncated; if, on the other hand, the secondary face is une<^ually inclined to the two 
faces, whiclj would form the edge of the crystal^ the edge in j*aid to V»o obi iqn ely trun- 
cated. The cube in ft/. 158 has it* edges j>er|^H^ndieiilarly, that in Jit/. IdO ba« them 
obliquely traucoted. If an edge of the dominant form ia replaced by two sinular 
faces, as in tho ctibc {^y. 160) it is said to be bevelled. In like manner, a solid anglo 
or summit of a crystal is said to be symmetrically or perpendicularly truu* 



Fiij. UB. 



Fit?. 159. 




/"^^ 




cated when it is replaced by a face which is equally inclined to all tho faces compo* 
sing the solid angle ; obliquely tru n cated when the trnnci%ting face is unequally 
inclined to those faces. Fitf. 161 is an octahedron with tho summits symmetrically 
truncated, Fitf. 162 an oblique rhombic prism, in which the solid angle to the right 
almre is obliquely truncated by tho face + P ao, which is unequally inclined to the 
faces ODp and oP. 

The fkce which replaces the solid angle is said to be set (or to rest) symmetrically 
or perpendicularly on an edge, when it is equally inclined to the two facea forming 
the edge ; obliq uely in the contrary case ; in^^. 16:2 the truncating face •h F as is set 




CRYSTALLOGRAPHY. 

Fig, 160. Fiy. 161. 



119 



ao* 



a»0« 




symmetrically or perpendicularly on the prismatic edge to the right, obliquely on the edge 
between oP and ooP to the right in front. The face replacing the solid angle is said 
to be set (or to rest) symmetricallv on a &ce of the pig^ xq2. 

crystal, when the plane angles which it makes with this * — 

fauce at the combmation-edge are equal, obliquely if 
they are unequal; thus, in fy. 162, the face -i- Pc» 
is set symmetrically on the face oP, but obliquely on 
the &ce ooP to the right in front 

A solid angle replaced by a number of faces which 
together make a more obtuse solid angle, is said to 
be acuminated. The number of the acumination- 

Fig. 163. 




AJ 




faces may be equal to, or hal^ or double of that of the original faces of the summit 
Thus the solid angles of the cube, which are three-faced, may be acuminated with 
three faces, bb in jfia. 163, 

or with sijc. as in ^. 164. ^^- ^^^' ^9- 166. 

The six-faced summits oifig, 
165, which is a formof calc- 
spar (L 722), are sometimes 
replaced by three-faced sum- 
mits, as in fig. 166. 

In prismatic crystals, t.^. 
such as are extended princi- 
pally in one direction, the 
terms bevdUng and acumina' 
turn are used to describe the 
conformation of the extre- 
mities. Fig. 167 is a six- 
sided prism, acuminated at 
each end by six isosceles 
trianffles, P, resting s^me- 
tricaSy on the prismatic 
&ce8. Fig, 168 is a quadratic 
prism acuminated with rhom- 
bic faces, P, resting symme- 
trically on the prismatic 
edffee. Fig, 169 is a rhombic 
pnsm, whose extremities are 
Wrellad bj MangoUr fiioef r oo, resting qrmmetrically on the acute prismatic edges* 




120 CHYSTALLOGRAl^HY. 

Fig. lez. i^y. 16Bw Fig, 169. 






In fdJ perfectly developed cryiitdJa ( witli a few cxcpptionfl^ to h& afterwarda 
considered as cu^es of heuiihedr)')^ every fncQ^ ^clgie^ or soinmit on one side or ex- 
tremity, Uaa ao equal and Biruilar face, edge, or Bummit oppoaite to it at the other 
Bide OP extremity of the cryetal, and if the opponte Batimiits, or the middle points 
of Dppobiie edges or faceii * be joined hy etraight linou* all lioe* m drawn wiE croaa 
one another in a Jiinfle point ealled the eentre of the crj'utaL Lines drawn through 
thin point and in to/St directionB that the faces of the crj'stal aie symmetrically dis- 
poser with Tespeet to them, are called Axes. 

Similar axes are those which terminate in similar parts of the crystals; dissimilar 
ttxeSi sneh as terminate in di^aimilar parts. In the regular octahedron (fy, 170), 
in which all the snmmita are similar, the three axes xjc*. ^ ^\ e r, joining thoaa 
■nmmita, are likewise similar. In tho double six-sided pyramid ( fy. 171), the horizontal 
axes which join the opposite four-faced Hninmitfi are similsr io each other^ but dis« 
similar to the vertical axis. 

Fig, 171. 





Volj-axlal mud Mono-axial Forms. Poly axial fbrms oi^ those in which no 
single axiij can be drawn dissimilar to all the rest, e.g. m the cul>e and regalar octahe* 
dron. Those forma, on the contrary, in whieh one or more axes can be drawn disnimilar 
to all the rest, are called mono-axial If only one each singular axis can l»e drawn 
in the crystai it is called the principal sxis, the others being called aes^ondar^ ; 
and in describing the crj"»tal* it is generally supposed to bo placed so thst the prm* 
dpal axis is directed from top to bottom (vertically, if it is perpendicular to the secon- 
dary axes). If two or more axes exiHt dissimilar to all the rest^ neither can be re- 
garded absolutjely an the princijml, hut it is uflual, for conTeniencc, to consider one of 
them as such, generally the one in whose direction the crystal is most elongated. Such 
an axis is called u relative principal axis. 

In monoaxial forms, the edges and summits through which the principal axis passes 
are called terminal, the othera lateral; thns, mfig. 171| the summits A A, and the 



* Th« mkldls Msint oti plane wrr^oe \g tlie ■anie' aK Ui centre of (^rarity; thai, in a triftnglei It !« th* 
point of InterteclUK] oftlie itr«isliit Hum drairn from ibe angltti to tho c«Dirc« of the o|?|KMltci ildet. 



CRYSTALLOGRAPHY. 121 

edges A B, &c., are terminal ; the summits B and the edges B B, which join them, 
are lateral. In polyaxial forms this distinction docs not exist. 

Mode of deserlbliiff Simple Cry-stallliie fomui. The form of a crystal is de- 
termined by the position of its &ces with regard to certain axes given in position. Sup- 
pose, for example, that the crystal is symmetrical with regard to three axes crossing 
one another at right angles, and passing through the same point, viz. the centre of the 
crystal (p. 120); then the position of each face of the crystals will bo given by the 
distance from the centre at which it meets the three axes ; and as all the faces of a 
rimple form are similar, and similarly situated with regard to the axes, the position of 
thin one face will determine the entire form. Thus, if each face of the crystal meets the 
three axes at equal distances from the centre, wo KhaU have a figure bounded by eight 
equal equilateral triangles, viz. the regular octahedron {Jig. 170); and if the distance 
at which the faces cut the axes be called a, such a figure may be denoted by the for- 
muLi, a '. a: a. A face which cuts two axes at equal distances from the centre, and 
the third at n times that distance, will in like manner be denoted hy a : a '. n a. If 
the number n be infinite, the face in question will be parallel to one of the axes (in 
other words, will not intersect it at any finite distance), and the formula will become 
a: a-. CO a, A face parallel to two axes is denoted by a : oo a : oo a. 

Zones. A number of faces of a crystal parallel to either of the axes are said to 
form a zone, or to lie in the same zone; thus the cube {fig. 160) has four faces 
parallel to each of the axes passing through the middle pointa of its sides ; so 
likewise each axis of the regular octahedron, loining the centres of the opposite edges, 
has a zone of four faces parallel to it ; the six prismatic faces of the ordinary form 
of rook-crystal {fig. 154), form a zone parallel to the vertical axis. The faces of a 
zone cut one another in edges parallel to each other, and to the axis of the zone. 

Bolobedral and Bemlbedral forms. A simple form, bounded by the greatest 
number of similar faces that can be arranged in different directions round the com- 
mon centre, is called aholohedral (fully developed) form; thus, the greatest num- 
ber of fi&ces that can meet three rectangular axes at equal distances from the point of 
intt-rsection is eight, the resulting figure being the regular octahe(bon {fig. 170), which 
is therefore a holohedral form ; but four such faces are suificient to form a closed figure, 
viz. the regular tetrahedron {fig. 190). Such a form, enclosed by only half the num- 
ber of faces that might be drawn round the centre, according to the law which deter- 
mines their position, is called ahemihedralform (half-developed). Simple forms 
iLso occur, containing only one-fourth of the number of faces that might exist accord- 
ing to the given law of symmetry ; such forms are called tetartohedraL 

Simple Crystals and Twin Crystals. Holohedral crystals, whose faces are all 
lymmetricaUy disposed about a single system of axes are called simple crystals (an 
expression not to be confounded with simple, form). Ciystals are, however, frequently 
met with, the opposite sides of which are symmetrically disposed round different sys- 
tems of axes. Such crystals are called twins (also m acl e s) : they may be regarded as 
ag^rt^tes of two simple crystals, having their axes more or less inclined to each other, 

CrjstaUocrapblo Sjrstems. The number of crystalline forms occurring in na- 
tur»- and produced by artificial processes, is so large, that some mode of classiiying them 
iii alisolutely necessary. All systems of classification are founded on the symmetrical 
dorelopmeut of crystals with regard to certain axes. 

The form of any solid whatever may be determined by referring it to three recti- 
lineal axes intersecting one another in a single point : and with regard to crystals, ob- 
•ervation shows that some are symmetrically developed about three axes intersecting 
one another at right angles ; others, with respect to axes more or less obliquely in- 
clined to each other : the former are called orthometric, the latter clinometric 
forms. Of the orthometric forms, some are equally developed in the direction of all 
thr*?e axes, others equaDy in two only, others unequally in all tliree. Some forms 
(the hexagonal) are more conveniently referred to a system of four axes. On these 
different modes of development are founded the following seven crystallographic systems : 

L The Monometric or Regular system, the forms of which are symmetrically 
disposed about three rectangular axes, all of equal length. 

n. The Dimetric or Quadratic system, the forms of which are symmetric about 
thn-e rectangular axes, two of equal, the third of different length. 

III. The Hexagonal system, the forms of which jire symmetric about four axes, 
thre<» of which are of equal length, situated in the same plane, and inclined to one 
another at angles of 60°, while the fourth is of different length and at right angles 
to the plane of the other three. 

IV. The Trimetric or Rhombic system, including the forms which are symmetric 
about three rectangular axes of unequal length. 



122 



CRYSTALLOGRAPHY. 



V. The Monoclinic syst^m^ including the formn which ore njtq metric about three 
axcfl, two ftt right angles to each other* the tliird (the principal axis), ppTpendicular to 
one of them and obUq^oe to tJie other. 

VI. The Diclinic Byitem, including forms which nre eymmetric about three oxe^ 
twt) of which are at right angles to each other* and the third oblique to tMith. 

YIl. The Triclinic ay stem, indading forms Bymmetric about three axes, all 
oblique to each other. 

The fint system compri^e^ the polyaxial fbrms ; the second and third, forraiS with 
alisolute principal axis ; the othens^ the mono-axial fornis with relative principal axis. 

Forma belonging to the same crystallographic «y»tcm are related to each other by 
Bcveral uatnral affinities. 

1. It 141 only the simple forma of the same iysittn, that can combine utto a c€^mphx 
form. — For in all fiilly developed (holohedral) natural ciyEtalB> it is ftmnd that all the 
fiimilnr parts, if modified at all, are modiiied in an exactly Bimilitr manner (in liemi- 
hedral formK, half the similar edges and angles alternately situated are similarly mo- 
dified). Now this can be the case only when the dominant form and the modifying 
ibrm are develop<?d according to the same law of 8ymlnet^J^ Thus, if a cul>a and a 
regular octdhedix)n arc developed round the same system of axes (as in fys. 156, 157), 
each summit of the cub© iB cnt off to the same extent by a face of the octahedron, 
or vtcf vcrsS. But a cube could never combine in this manner with n rhombic octa- 
ht^dron, because it would be impoesible to place the two forms in such a manner that 
similar part« of the one ahould throughout replace similar parts of the other. 

2. Crysialjt bd&nging to the mme syHfm are iniimaidif related in their opiictil 
properiueu—CijBiim belonging to the regtdar system (as the diamond, alum, rock-*iult, 
&c\ refract li^ht in the some manner as amorphons bodies ; that is to sayj they hare 
but one rpfractire index^ and a my of light passing through them in any direction is 
refracted singly. But all other crj'stals refiroct doubly, that is to say, a ray of light 
passing throng them (ejccept in certain directions) is split into two rays, the one 
called the ordinary ray, being refracted as it wonld be by an amoiphous body, the 
other, called the t^traordinary ray, being refracted accorJing to peculiar and more 
complex laws (see Liqut), Now the crystals of the dimetric and hexagonal 
f^stemj (those with an absolute principal axis) resemble each other in this respect^ 
toat in all of them there is one direction, called the optic axis, or axis of double 
refraction (coinciding with the principal crystallographic axis), along which a ray of 
light is refracted singly, while in all other directioim it is refracted doubly ; whereas 
in crystals belonging to the other systems, viz. the trimetric and the three clinometric 
(pystems, there are always two directionH or axes, along which a ray is singly refracted. 

3. Cri/«tal» Momjing to the same s^sirm rtJtemhlr each other in iileir modt of con- 
ducthfff h^nt. — Amorphous bodies and crystals of the regular system conduct heat 
equally in all directions, so that, supposing a centre of heat to exiat within such a Ixidy, 
the isothermal surfaces will be spheres. But crystals of the dimetric and hexagonal 
systems conduct equally, only in dlrectiona pemendicnlar to the principal axis, so that 
in such crjrstala the isothermal surfaces are ellipsoids of revolution round that axis ; 
and crj'stals belonging to either of the four otiier systema conduct unequally in aU 
directions, so tliat in them the isothermal fiurfoces are ellipsoids with three unequal 
axes. (See II eat.) 

ICon o 111 « trio or SefvlftT ayBtein* 

T^'^stfinr^ Isometrie^ or Cubic System, — All forms of this pystcm are similarly and 
equally developed in three directions at rieht angles to each other ; in other wortls, 
they are symmetrical al>ont three rectangular axes meeting in a common eentre. The 
position of each face is determined by the distances tram the centre at which it 
meets the three axes (p, 121.) the following being all the cases that can occur : — 

A 1. EiwJi face (extended if necessajy) meets all three axes at eqiial distances from 
the centre : the formula of such a face is « : a : a. 

B. Each face meets two of the axes at equal distances from the centre, and tiio third 

at A different distancei : 

2. Each face meets two of the axes at an infinite distimce from the centre (i. t* it 
is parallel to these two axes), and the third at a finite distance. Formula 
a : oa ^ : 00 a. 

3. Or two axes at equal and finito distances, the third at an infinite distance, 
a : a t OB a, 

i. Or two axes at equal and finite distances from the centre, the third also at a 

finite but less distance. Formula a \ ma \ via [m > l], 
5. Or two axes at equal aud finite dii^tances, the third at a greater distance. 

Formula a i a: w « [wt> 1]. 

C. Bach face ctits the tliree axea at different distances from the centre : 



MONOMETRIC SYSTEM. 



123 



6. Two axes at finite, the third at an infinite distance, a: ma: co a. 

7. All three at finite distances, aim a: n a. 

We now proceed to determine the forms giyen bj these several conditions. 

1. The form in which each face meets all the three axes, xx, yy, rr, at equal distances, 
a, fiom the centre is eridentljr bounded b^ eight equilateral triangles. This form is 
the regular octahedron {fy. 172). It has twelve equal edges, in which the faces 
meet each other at angles of 109° 28', and six equal four-faced solid angles or summits, 
through which the- axes pass. A summit thus situated, in any form of the regular 
system, is called an octahedral summit; where such summits occur, they are always 
nx in number. 

The ciystallographic formula of the regular octahedron is a : a : a, usually abbre- 
viatod into the symbol O. 

The regular octahedron is the form of many crystals, both natural and artificial ; 
e.g. red copper ore, magnetic iron ore, alum, chromc-alura, sal-ammoniac crystal- 
liaed from its aqueous solution, chloride of sodium from a solution containing urea, &c 



Fiff, 172. 



%. 173. 




^^--^ 


f -^1 




floQeB 






,1.-.. 




.X 




^ 






„-- 




*' 


^ 



Fig. 174. 



2. The simple form a : oo a : oo a, or c» O oo, in which each face meets one axis at 
the finite distance a, and is parallel to the other two, is evidently the cube or hexa- 
hedron (fig, 173), bounded by six equal faces, intersecting one another at right angles, 
and each having the form of a square. It has twelve eqaal edges meeting one another 
at right angles, and ei^ht three-faced, equal-edged, solid angles or summits, situated in 
each octant at equal distances from the three axes. iSummits so situated are called 
hexahedral or cubic; in holohcdral crystals they are always present to the number 
of eight, if at all. 

Cubic forms are frequently exhibited by bismuth, chloride of sodium, iodide and 
chloride of potassium, sal-ammoniac crystallised from a solution containing urea; also 
by fiuor-spar, galena, and other minerals. 

The cube and octahedron aro often found combined together ; the one or the other 
form predominating, according to the relative length 
of their axes (Jigs. 166, 157, p. 220). If the axes 
of the cube aro less than half as long as those of the 
octahedron, the combination is a modified cube, like 
that in Jig, 174. If; on the contrary, the axes of the 
rube aro moro than half as long as those of the oc- 
tahedron, the combination is a modified octahedron 
(Jig. 176). If the axes of the cube aro exactly half 
as long as those of the octahedron, the faces of the 
two forms meet only in points, and the combination 
is that shown in Jig. 176, called the middle 
crystal. It has twelve summits, each of which 
is situated in the plane between two of the axes, 
and at equal distanceB firom them. All summits 
thus situated in forms of the rogular system aro said to be situated, 
of the middle oystal." 

3. The formula a : a : oo d, or oo 0, represents a solid, each of whose faces meets two of 
the axes at equal distances, a, from the centre, and is parallel to Uic third ; it must 
thereforo have twelve faces, four parallel to each axis. To define its form more parti- 
cularly, draw the system of rectangular axes jp j/, y y', g z\ meeting in C ifig 77), 
and set o£f on them the points x,x', y,r/, ^,^, all at equal distances from C. Now the 
face passing through z y, and parallel to x x', will intersect the face passing through 
j' y, and paraflel to « y, in the line a/, aim parallel to x j/. Similarly the faces 




' like the summits 



124 



CRYSTALLOGRArHY. 



^1^. 175, 



%. 176. 






/\ 



x^jv:^,^^ 



parallel to yy*t tnd pftuuig PospcctiTely through z x, s' 3c^ will iDtersect in rf/ pftmllol 
to ^ y, and the linen zf, ^ f^ in which thoso paim of faces intersect, form two edges 
of the crvBtaL Extending this conatrnction all round the axes^ we find that the four 
fiKH*.s Tii(*eting in r, and the faiir meeting in s*, would, if extended till they intersect, 
form a double four-sided pyramid, ropresented \nfy, 177 and by the dotted lines in 
fig. 178* But there are si ill the faces ptiraJlul io z ^ to be liiiivni. One of thes^ faces 
passes through llio line x y^ and ita p<j«itioa may be determined by drawing through 
the middle point of t if {fi^. 178), a lino r k, parallel to z r', which will cut the e(ige 
c/o£ the py rain id in its middlo point /; and by joining this point with the poiata^r^y, 



Fiff, 177. 

r 



Fig. 178. 




> 



1* 



fre obtain two edges of the required form, / x, I y. A similar construction carried out 
in the other parts of the figure finally gives the t h o m hi i? d o d e c ah ed ron (also called 
granatohedron). It has twelve rhombic faces, with plane angles of 109'^ 28' and 70° 32', 
and diagonals in the ratio of 1 : V2. The cdgtffl are all equaL Tlie summits are 
fourteen in number, six 4-faeed, octahedral summits, A.(fy. 161), formed by the meet- 
ing of the acute anglea of the rhombuses, and eight S-factnl cubic summitif, B» formed 
by the meeting of the obtQM edges of the rhombuses. The dihedral angles formed 
hy the meeting of the fiices are adl w^ual to 120°, 

The dodecahedron somettmea occutb alone in artificial crystals, more irequently in 
combination ; in minerals it ia moire eommoo as a simple form, as in garnet. 

The three forms above described, the regular octahedron, eube, and rbombic dodeca- 
hedron are unique in thetr kind ; that is to say, all indiTiduals of each species must 
be exactly similar to each other ; there can b© no Trariation either in the plane angles 
or in the inclination of the faces. This, indeed, is sufficiently evident from the for- 
mnlfl?, which admit of no Turiation, and from the mode or construction. But iti 
the remaining four forma of the regnlar system, the formulsa of which contain nu- 
merical coefficients iidmitting of v&rmtiona in maffnitnde, this constancy of sha|>e no 
lonffer exists ; and accordingly we shall find that the angles vary with the magnitude 
of Uie coefficients in the formula. 

4- The formula a : ma : mo^ or m m, represents a solid, each of whose faces m(«et^ 
one axis at the distance a from the eentro, and the other two at the greater distance m a. 
Draw a system of rectangular axes {fy. 179), ajid, taking for example m ^ % mark otT 
single and double distances, x, lot, &c,, on each of the tlm^e axes. It is then easy to 
see that the position of one fuce will be determined by a plane passing through the 
points y, 2*, 2j; a second through y, %s, 2^1 a third through y, 2y 24:^ ♦; and a 

■ Thr< poiaLi m^, ]^, x\ *c. (not ihowa In the lijgura) Ate tuptHiicd to be ou th* t^rolonigalloni of lbs 
Uiicif tC, yC xC, u In the precedbg^ figure. 



MONOMETRIC SYSTEM. 



125 



fourth through y, 2*^, 2x ; that is to say, there will be four faces meeting at the point v 
and in like mannep there will be four faces meeting in each of the points t s^^v' e g* 
or 24 in all, three in each octant » » J^» » » 

Further, the face y, 2^, 1x^ will meet 



^. irs. 




the face y, Iz^ 2«', in the line y, 2xr, 
and the &ce ^, 2y, 2x will meet the 
iace r, 2y, lif in the r, 2y, meeting 
jr, 2^ in the point e. Thus the edges, 
cy, cz^ situated in the plane y^, 
are determined ; and a similar con- 
struction gives the edges ax, ay, 
and b X, b t. Next, to find the in- 
tersections of the three faces in- 
cluded within the octant x y e. The 
face r, 2x, 2y, intersects y, 2x, 2z in 
the line e, 2x, joining ix with the 
intersection of r, 2y, and y, 2g ; the 
face jr, 2y, 2r, meets y, 2f , 2jr in the 
h'ne dAwn from 2jr to a, the inter- / ^} 
section of *, 2y, and y,2x; and jr, ^J^" 
2y, 2? meets r, 2r, 2y in the line 
drawn from 2y to b, the intersection of x, 2r, and r, 2f . This construction gives the 
intersections shown bj the dark lines in the figure, and determines the form and posi- 
tion of the three faces in the octant xys; and the same construction repeated in the 
other octants gives the form shown in Jigs. 180, 181, which is called theikosi-tetra- 
Fig. 180. Fig. 181. 





hedron (also leucitohedron and trapezohedron). It is bounded by 24 deltoids (qua- 
drilaterals haying two unequal pairs of equal sides), and has 26 summits, which are 
of three kinds ; viz. six 4-faced, equal-edged, octahedral summits, A ; eight 3-faced, 
equal-edged, cubic summits, B ; and twelve 4-faccd ^mmctric summits, C, situated 
like the summits of the middle-ciystal (p. 123). It has also 48 edges, which are of 
two kinds, riz. 24 longer, A C, joining the octahedral with the symmetric summits, 
and 24 shorter, B C, joining the cubic with the symmetric summits. 

The ikofli-tetrahedron is the intermediate form between the octahedron and the 
cube ; for m — 1, it coincides with the octahedron ; for 7n « oo , with the cube. The 
nearer m is to 1, the more do the three faces in each octant fall into one plane, and the 
more nearly m » oo, the more do the four faces round each octahedral summit, A, fall 
into one plane, the limit giving a cube. The inclination of the faces to one another 
in the longer and shorter edges is : — 

AC . BC 

In 2 O 2 1310 43' HG^ 27' 

,,303 144 54 129 31 

The form 2 O 2 is found alone in leucite, analcime, and other minerals; 3 3 rarely, in 
native gold, silver, &c In artificial crystals, the form 2 2 occurs combined in chrome- 
alum and common alum, when a crystal is immersed in a saturated solution mixed 
with a little hydrochloric acid slightly heated, so that the edges may be dissolved off, 
and then left to cooL 

6. Formula a : a : ma, or m 0, each face meeting two axes at the distance a from the 
e<>ntre, and the third at a p^eater distance, m a; m being either a whole number or a 
fraction givater than I. This form, like the preceding, has 24 faces, 3 in each octant. 
A eODStmetion rimilar to the preceding, and suificiently indicated by the fUll and 



126 



CRYSTALLOGRAPHY. 



Fig^ IWL 



Fig. 188. 





dotted lines in fig. 182, bIiowh tliat the solid is bounded by 24 isosceles tri&ngulsr faces, 
nw\ Las the appcurance of an oetah^^lron with triangnljur pyramids erecUnl on its ftices^ 
This fomi ia cjiLIlhI the triakis-octabedron (alflo pjmmidal octahedron, giJenoid). 
Fig. 183 shows the form 20* 

The triakis-octrthedron him 14 aummits, six of which^ A, aro S-faced, aytnmetric, 
and ocUihedral^ and eight 3 -faced, iNgual edged, and cubic, B* The edj^es arc also 
of two kinds ; 12 A A, joining the octahedral summits and forming the hases of the 
iso®celett triangles ; and 24 A B, joining the octaliedral and cubic smDmita^ and 
forming the e^jual sides of the triangles. 

The triakis-octaliedron, ai (l\ ma, is the interroediate form between the octahedron, 
a : a \ etj and the rbombuc dodecah&droa, a: a looa. 

The plane and dihedral angles vary with the value of mj aa in the following ex- 
amples ; -— 

10 20 

Plane angles at vertex of isosceles triangles , . llfi^ 14' ll&° 4* 

Plane angles at base of triangles . . » . 30 23 30 58 

Dihetlml aiiglea A A 129 31 lfl2 39 

Dihedml angles A B 141 3 152 44 

6. Fomjula a : ma : oo fl, or mO oc, eath face me*^tLng two of tho axes at un«|ua] 
distani^ei* and being paralM to the third. To determine the ntimh« of fkoc« in this 
form, mark off, on the system of rectangular axes {fg. 184. supposing m —2) ftingle and 
double distances on e^ch of the axes measured from C. Then there will be four faces 
pafwing through the point 1 y> two parallel to x x\ tlirough the points 2 c and 2 r', and 
two parallel to sif^ through the points 2 J, 2 a*'; and since the crj-stn.! is equally deve- 
lopeu in the direction of ^ the three axes, there ntust be four simihir fiice^ meeting in 



Fig. 134, 



Fig, 18fi. 




each of the points /, *, x', *, s^, that ta to say, twenty-foni' facoa in all j and by con- 
stmcting each octant in tlie same manner as for the preceding foniiulffl^ the form is 



MONOMETRIC SYSTEM. 



127 



fbnnd to be a solid {fig, 186), bounded bj 24 isosceles triangles, having 14 summits, 
Tia. four 4-£iiced equal-edged octahedral summits, A, and eight 6-£eu:Ml sjrmmetric, 
cubic summits B. It has 36 edges, 12 longer, B B, uniting the cubic summits, and 
24 shorter, A B, joining the octahedral with the cubic summits. This figure is the 
tetrakis-hexanedron. It is intermediate between the dodecahedron a : a : ooo, 
and the cube a : oo a : oo a. In the more commonly occurring yarietieS) the plane and 
dihedral angles are : 

20qo 30 00 

Plane angle. A, at vertex of isosceles triangles 83^ 38' 86° 59' 

Plane angles, B, at base of triangles ... 48 11 46 30 

Dihedral angles, A B 143 8 164 9 

Dihedral angles, BB 143 8 126 52 

The form 20 oo occurs uncombined in native gold and silver; SOoo in fluor-spar. 
In artificial crystals these forms occur but seldom, and then only subordinate to others, 
as fur example in sulphantimonate of sodium (Schlijppe's salt), and in rock-salt which 
has been exposed to moist air. Faces having the disposition of this form, but in only 
half the full number, are of more frequent occurrence. 

7. Formula a : ma : na, or mOn. Each face meets the three axes at unequal but finite 
distances. Such a form must have 48 faces ; for through each axial extremity 2 faces 
can be drawn in each of the four, conti^ous octants, e, g. from t above, one face pass- 
ing through the point itia or dr to the right, and fia or y in front, and another through 
lui or jr to the right, and 7na or y in front ; therefore, 4 x 2 ^ 8 through each axial 
extremity, and 6 x 8 » 48 in alL 

To determine the form of these faces, draw the system of axes as before, and taking 
as an example the form 1 : J : 3, or §03, mark off on each axis {fig, 186), both ways, the 
distances 1, f, and 3. The fiu!e t'.^y. 3x, forms with the face 8\\if\ 3x'(not drawn 
in the figure), an edge in the direction «r, |y. The same face r, \^ : Zx intersects the 
£Me r, 3y, |jr in the direction ro, drawn through e and the intersection of the lines Jy, 3x, 
and 3y, \x ; and lastly, it intersects the face y, |^, 3jr, in the direction 6, 3j:, where h 
is the point of intersection of the lines ^, fy, and y, \s. The face thus determined is 
a triangle, and in like manner the position of the five other faces in the octant, xy e^ 
may be determined. The result extended symmetrically to all the other octants, is the 



Fig, 186. 




Fig. 187. 




^^j Jiff ^i^LViia^ ^-sar 



form represent^ in fig. 187, bounded by 48 scalene triangles. This figure is called 
the Hexakisoctahedron (also Utrakonta-octahedron, adamantdid^ &c). It has 26 
summits of three kinds, viz. eight 6-faced symmetrical octahedral summits A, through 
which the axes pass ; six 8-fiiced, cubic summits B ; and twelve A-fauc^A. symmetric sum- 
mits C, situated like those of the middle crystal (p. 123). Its edges are 72 in num- 
ber, and likewise of three kinds, viz. 24 edges A C, uniting the octahedral with the 
four-faced summits ; 24 edges B C, uniting the cubic with the four-faced summits, 
and 24 edges A B, uniting the octahe<lral with the cubic summits. 

The plane and dihedral angles of the figure vary with the magnitudes of m and n : 
for the most commonly occurring forms they are as followsj 

Plane angles A of the scalene triangles 



*f 


B 




n 







Dihedral 


angles 


AC 


ft 




BC 
AB , 



30^ 
. 360 49' 


204 

390 48' 


. 56 15 


54 22 


. 86 56 


85 50 


. 149 


154 47 


. 158 13 


144 3 


. 158 13 


162 1« 



128 



CRySTALLOGKAPIiy. 



The form 204 often occurs very predoTninatit in crjfftalii of flnor-spari 3D| in garnet. 
Diamonds are also found having the form of the hextikis-oetaliedron, but with cmnred 
faces, fto that the angles cannot be accnrutely raeatsured. This form occnrs but rery 
raroly in artificial crystals : it hiis, however, been obiurred, ihougli very subordinate, in 
alnm cryytidliHed from a solution coiiUiining hjdn>cblorii: acid. 

BenoUiedrftl Tormm of tlio Secular Ssfstem.— Snppoae foor altemato fkces 
of the ooljibt diviri (^. ISS\ vii. iho. right front n\mY*\ left front below, left, back iiboTe, 
lind right ba<:k t>elow, to ext4?nd m &n partially to obliterate the foor remaining fiices ; 
a form will be produced like figure 189; and if the «it*>nsion be continued till the 
aitamate fkcea eomploteJj disappear, the four-aided pyramid {Jiff. 190) will bo pro- 


duced, called tho regular tetrahedron, and denoted bj the symbol -s-, 

Fig. 189. 





It is bounded by fonr cqnDnteml triangle, baa 4 three-facpd summits, and 6 stmilar 
edges in wbicli tbe &C6S are inclined at anghs of 70"^ 32'. The aies pjisa through tho 
middle points of each pair of opposite edges. 



Fif/. 190. 



Fuj. 191. 





If the other four aides of the octAhe<iron iocpcase instea*! of those Above-mentioned, 
tlio reiralt wiU be tho tetrahedron »hown in ftgnro 191. exactly i^imilar to the former 
bat oppositely litotitod When both th^se tetrahedrons occur together in tbe aamo 

6rjst&If fks in fy. 189, one of them is distinguisbod as ^ — the other as — ^ ; when 

cither occnrs alono tbe sign + or — may be omittt»d. 

Tetrahednd faces ocouj in Schlippe's ealt» chlorate of sodium, fahl-ore, blende, &c. 

The cub© and rhombic doJecjihedroi* have no corresponding hemihedral forms. 
The icosi-ti*tmhedron, triakis-ootabedron, tetrakis-hejtahedron, and hexakis-octa^ 
hedron all produce hemihedral forma by tln3 growth of their alt<?mate face« ; but the 
only one of these forms that it ia importtint to notice ia the pentagonal dodecahedron 
{Jiff. 192) produced from the tctrakis-hL'Xiihe(b>m(jJ<7. 186, p. 1*26)- This holohedral form 
may be regarded as a cul>e on esich of whose six faces m erected a fonr^sided pyramid. 
Suppose now that on the top and bottom pyramids, the front and back faces grow, 
while the right imd left diaappear ; that on the front and back pyramids, the right and 
left faces grow, while the upper and lower faces disappear ; and that on the right and left 
pyramids, the upper and lower facets grow^ while the right and left disappear ; the result 

will be a dodecahedron whose general symbol is — — . Fit}, 192 reprenenta - — . 

If the other alternate faces of the holobcdral form be sapposcd to increase^ an exactly 



MONOMETRIC SYSTEM. 

Fig. 192. BHg. 193. 



129 





■imilar dodecahedron (fg, 193) will be formed, but dififorentlj situated ; the^e two 
fonna may be distinguished by the symbols + -5 and --— . 

The pentagonal dodecahedron is bounded by 12 fiymmetric pentagons, each haying 
four of its sides of equal length, and the fifth (the base) of different length. It has 
30 edges, 6 of which, £ E, are formed by the meeting of the faces at their bases, and 
24, B K forming the equal sides of the pentagons. The summits are 20 in number, 12 
of which, £, formed by the meeting of a basal edge E E, and two equal edges B E, are 
situated in the planes of the axes, but at different distances therefrom, and 8 others, B, 
formed by the meeting of three equal edges of the pentagons and situated like the 
sommits of the cube. The axes pass through the midcUe points of each pair of 
opposite basal edges. 

The pentagonal dodecahedron has not yet been obeeired in its complete form in 
artificial crystals; among minerals it is especially exhibited by iron-pyrites and 
colialt-glance. 

Combinations of the Blmplo Forms of the Monometrio sjstem. These 
combinations are vciy numerous ; we shall here notice some of the most important 
In expressing a combination symbolically, the symbol of the dominant form is usually 
vritten first: 



Fig. 194. 



Fig, 195. 





Fig, 196. 



Fig, 197. 





1. Cube and Octahedron : 

O . OD O OD (fia. 194). Alum, chlorstannate of ammonium, cobaIt-pyrite& 
o»0 OD . O {fy, 196). Chloride of zinc, galena. 

O and ooOoo equally developed (fy. 19G), forming the "middle ciystal" 
(p. 123). Nitrate of lead. 



130 CEYSTALL06EAPHY. 

rig. 198, ^- IW- 



Y — ^ 



W 



a>0 A 



i^. 200. 




J\^. 202. 





FHj 201. 




Fi^. 203. 




la. Cube and Tetrahedron: 

^ . ooO 00 {fig, 197). Boracite. 

a» 00 . 7 ( j^. 198). Boracito, Cabe-ore. 

2. Dodecahedron and Octahedron: 

O . ooO (^. 199). Alum and red copper-ore. 
ooO . (Jiff. 200). liagnetic iron-ore. 

2a. Dodecahedron and Tetrahedron: 

^. ooO (fiff, 203). Sodio-nranic acetate. Fahl-ore. 

8. Dodecahedron arid Cube: 

ooO . 00 O 00 (^. 201). Garnet (rarely). 

ooO 00 . ooO {fiff, 202). Alum, crystallised from solution containing tree alkali ; 

chloride of potassium from solation containing mercnric chbride, frequently ; 

flnor-spar rarely. 



MONOMETBIC SYSTEM. 

Fbf. 30*. BHg. 205. 



131 




(^^^P\ 






E*^ 



i^.206. 



Fig. 207. 





coO« 



AJ 



Fig. 208. 



j^^. 209. 





4. Dodecahedron^ Cube and Octahedron: 

O . 00 O 00 . ooO {fig. 204), in wliich, however, the O-faees do not predominate 
very mnch ; occurs commonly in alum. 

oo O 00 . O . 00 O {fia, 206); fifeqaently in alum from solution containing free 
alkali ; also in chloride of sodium from solution containing chloride of bis- 
muth. 

4<z. Dodecahedron^ Cube and Tetrahedron: 

These combinations, which occur in Boradte, are simOar to those of the 
dodecahedron, cube, and octahedron, excepting that only four octahedral faces are 
present instead of eight 

6. CombinationM of Icosi-tetrahedron : 
00 0.202(^.206). Melanite. 
a>0 » . 202 {fig. 207)u Analcime. 

O . 00 00 . 202 (jM. 208). Alum and chrome-alum (rarely), 
O . Q» Ooo . OD O . 202 (fig. 209). Alum. 

k2 



132 



CRYSTALLOGRAPHY. 

Fig. 210. Ftff. 211. 



PI /^^\ 



J7 



Fig. 212. 



F^. 213. 





Fig. 214. 



f^l\ 




B, Combinaiions of the Tetrakii-kexake- 
dron : 

OD O OD , 30 w> {^. 210), Fluor-spar. A 
iiiniil»r combination^ oa oo , 20 ao, is pro- 
tluced wlieci cubes of rock-salt are expo«cd 
to moifit air. 

QoOoo. + (Jig. 211). Iron pyiitca. 



Oob^ltine. 
O, c»Oo& . 060. 202 
{;%r.212). Alum. 



20 a 



20; 



7. Combinations of the Hexakis-oetahedron : 
O . 30| (^. 213). Alum f apparently). 
ooO 00 . 2d4 (fy. 2U). Plaor-Bpar. 



SlinetTlc or ^nadratlo System* 

Square Prismaiic, Pgramidal^ Tetragonal^ Monodimetric System {Zmd- wtd nnajeujts^ 
vierqtiedrigrs System), 

dtyBtiila belonging to this system are symmetric a)M>at tbreo rectangular oxefl* two 
of ocjuul, the third of different length ; and may, therefore, be so placed aa to appear 
<H|ually <leveloped in t.MTo borkontal directions at right anglrs to each other (Hii^ht and 
h'ft., and backwanis and forwards), btit difftirently in the vertical direction. The rer- 
ticxil or principal axis (p* 120) will be denoted by c, the horizontal or fteeondaiy ajces 
by ii. AH sections perpendicular to ths pnudpol axis are squares or figures derived 
therefrom. 

In tbii, as in the monometric system, the most general form is one, each of whowe 
&oes (produced if necessary) meets tbo three axes at different distances from tiio 
centre, liet these distanees be a and na for the secondary axes {n beinp a mnltipUer 
either gre!it4?r or less than unity), and c for the principal axis. To determine the 
form, draw two recLinppilar axes {fig. 215), and supposing, for example, n = |, set off 
from the centre the distances a and | a, and join each ix>iut. a on the one axis with 
§a on the other, a« shown hy the dotted lines in the left up|>er qmidrant. The portinns 
of ^ew lines contfdned Iwtween the sevenil points a and the intersections of these 
dotted lines mil form an equilatejral octagon ; and if fmm each of the angles of this 




DIMETRIC SYSTEM. 

Fig. 216. Fig, 216. 



133 





octaf^n straight lines be drawn to the extremities o of the principal axis (perpen- 
dicular to the plane of the i>aper), the planes passing through these lines will enclose 
a double eight-sided pyramia {/g. 216), bounded by sixteen scalene triangles, ABC, 
the summits B being situated at the ends of the horizontal axes, and the summits C 
at angular distances of 46^ therefirom. This figure evidently fulfils the condition 
essential to the forms of the dimetric system^ of being equally developed in the direc- 
tion of two rectangular axes, but dififcrently in the direction of the third. It may be 
represented by the formula : 



The inclinations of the edges B C to each other (or the angles of the octagon, fig, 215), 
vary with the value of nu The more n approaches to unity, the more nearly do the 
points n a {Jig. 216) approach to a, and the more nearly do the lines joining these 
points (B C, C B in^. 216) approach to coincidence, the angles C of the base becoming 
peafer ; and when n = 1, or the formula becomes a: a\ c\ the angles C become = 180° ; 
u other words, the lines B C, C B coincide ; the octagon becomes a square ; and the 
double eight-sided pyramid is reduced to a double four-sided pyramid with a square 
bMe {fig, 217)» having its angles B situated at the extremities of the horizontal axes. 





If, on the other hand, n increases, the angles C {fig. 216) become less, and the 
angles B more and more obtuse ; and finally, when n « oo , or the formula becomes 
« : oe a : r, the angles B became « 180°, or the two horizontal lines B C, B C, drawn 
from the extremities of each axis, merge into single straight L'nes parallel to the other 
axis ; and the base of the pvramid becomes a square, having the middle points of its 
sides at the extremities of the secondary axes, and its angles C equidistant from those 
points, as in fig. 218. 

The sjrmbols of the three forms just described are abbreviated as follows : — 

fl : a: {fy. 217) - P 
a : na : c {fig, 216) « Pn 
a \ ooa : {fig. 218) —Poo. 

It appears then that a square pyramid may be represented by the formula a : « : c=P, 
ora:ooa:c««Poo (the ratio c : a being however diflferent in the two cases), 
aoeording as the secondaxy axes pass through the angles or the middle points of tho 
sides ofthe base. When two p\Tamids so related to each other occur together in the 
nme distal, P is regarded as the primary form, and is called the square pyramid of 
the flnt osdeor ; P oo the pyramid ox the second ozder. 



134 



CRYSTALLOGRAPHY, 



A square pynynid is more or less atmte, acconliiig t<5 the patio betiroen tlie principal 
and secondnipr axes. When a is very aejwly pqual to c, the pynimid is scarcely dis- 
tinguishable m outward form from th»> regiilar octahedron (fy. 149) ; the two forms may, 
howerer, always be distinguiiilicKl by their modificatiDns, the edges and smnmits of the 
regular octahedron being nil modified alike^ whereas in a square pyramid the tjermimil 
edges A B {fy. *210) may be modified difil'reDtly from the lateral edges B B, tind the 
summits A A at the ends of the pnQcipal axis difl&n^ntly feom the summits B at the endf 
of the Be<!ondaTy axes. 

Ah the ratio of c to a becomes greatijr, the pyramid becomes more and more a^nte^ 
and tbe angles of the planes meeting in the lateral edges B B(/^. 217), C C {fy. 218), 
or Ji C (^. 216), approach more nearly to 18<F ; and finally, when the ratio c :« be- 
comes inllnitely great, this an^lc becomes = IBO*^, and tbe pyramid is reduced to a 
prism of indetlnito kogthf having its sides parallel to the principtd axis. 

When two qnadratie pynumidla, in which the ratio c : aia dilFerent, occur together 
in the same crystal, one of them is regarded as the primary form, and denoted by one 

of the formuliB already given; the other in which the ratio of - is i» times tJiat in 

the former {m M), is denoted by prefUing thu symbol m to <? in the full formula, or 
to P in the abbreviated formula ; thus i — 

Square pyramids of the first order » . . a : a : mo = mV^ 

Octagonal pyramids , a : na : fito ^ mVn 

Square pyramids of the second order , . . a : vaa : ftto ^ wiPa> 
When in either of these formuhe m becomes infinite, the corresponding pyramid becomes 
a prism, as already explained. 

When 771 B» 0, the pyramid is replaced to a plane, eaUed the tafminal face, or 
end-face^ oP, parallel to tbe plane of the secondary axes. 

Among pyramids of the second order occurring together with a primary form P, it 
is usual to distinguish particularly the two following : 

a. The next ODtuaer pyramid is that whose faces have the same position and in- 
clination with respect to the principal axis, as the t^^rminal edges of the primary form. 
For the primary form a : ii : c, or P (Ji^. 217) ; the next obtuAer pyramid is evidently 
a : 00 a : p, or P Qo {fy. 218), having for its base the outer doited aquar*^, he/d (fy. 219)» 
whose sides are drawn parallel to the axes, through the angles of the base of the 
primary form ; and generally, for everj^ square pjromid of the first order, mF^ the next 
obtnser pyramid is tkFco . The terminal edges of P are symmetriciiUy truncated by 
the faces of wPoo . 

b. The next acuter pyramid is that whose terminal edges have the same posi- 
tion and inelination with respect to the principal oxis^ as the faces of the primary 
form. The primary form having for its base the equare represented by the continuous 
lines in JU/. 219, Ihe next atniter pyramid will have the same prineipul axis, and the 
bftse^ A kf, whose angles arc at the middle point* of the sides of tlie primary form. 
The fomiula of this pyramid is ia : ao ij : f?, or a : oo a : 2<:', or 2Pod ; and genoraily, for 
CTery square pyramid of the ftrst order, //iP, tho coiTc^ponding next acuter pyramid is 
2mPi30 . Tho terminal edges of the latter are symmetrically truncated by the fiices 
of mP. 

Fiff, 21^. i^. 220. 





Cont^inatloiu of tlie BoloiiedTal f^^Tiiu of the 2>lmetrf c i yite m. Tho 

square and octnftnnal jsyrjimidH suid pritims above degcrilud nre tho only Himplo holo- 
hetkid fonnw of Uie dimetrie KyHlem. Tho fo I lowing ar*? R4»me of tlveir principal com- 



A 



DIMETBIC STSTEIL 



185 



buttdons: — When t«o tqiure pyraini,d8 of the same order oecax toother in a crystal, 
tiie more aeate of the two is acuminated in the direction of the principal axis by the 
Uem of the more obtoee^ which rest on the faces of the former, as in j^. 220. In 
filpK^i» of nickel, which crystallises in this manner, the ratio o : a ■- 1*888 in the 
man acute, and 0*944 in the more obtose pyramid, the len^ of o in the two pyra- 
mids referred to a seoonda^ axis as unity, being in the ratio of 2 : 1. In all such 
combinations, it is found that the princifMil axes of the two pyramids bear to one 
another a simple ratio, as 3 : 1, 3 : 2, &c 

When two sauaze pyramids of different ordera occur together, the faces of the one 
traneate the eoges or the summits of the other. Fig, 221 represents a form of tin- 
stone, in which the terminal edges of the primary form P are symmetrically trun- 
cated by the faces of the next obtuser pyramid Poo . Fig, 222 is a form of anatase, in 
which the terminal summits of P are acuminated by JP, and the lateral summits are 
berelled by the &ces of the next acuter pyramid, 2Pao . The terminal edges of this 
Utter pyramid may also be regarded as yezy broadly truncated by the faces of P. 



^.221. 



Fig, 222. 



^.223. 



J^. 224. 




^ *^l \ — 

r 1 ' ■ 

t i * 

• I * 

I i 




OmbmrntioBS of prisms and pyramids of the different orders, with or without the 
terminal face oP, are of frequent occurrence. Fig. 223 represents an octagonal prism 
formed by the prismatic faces of the first order, oo P, tnincatod by the prismatic faces 
of the second order, ae Poo , and terminated above and below by oP. This form is 
seen in acetate of copper and calcium, C*H*CuCaO'. 

«P.P (^. 224) 18 a form of potassio-uranic acetate, a square prism with pyra- 
midal summits resting on the prismatic fiices. 

Fhe. 225, 226, 227 represent combinations of the forms P . oo P oo in rarious pro- 
portKma. 

P . OD P OD (Jg. 226), with P predominant, is found in mcllite or honeystone. 

P and 00 P OD equally developed (fy. 226), which has very much the appearance of 
a riiombie dodecahedron, is exhibited by potassio-cupric chloride, KCLCuCL 

ac P CO . P (Jig. 227) is a form of apophyllite. 

Fig. 226. Fig. 226. ^9- 227. 






The following figures (Jigs. 228—231) represent combinations of square pyramids with 
the terminal fiwie oP ; they are all forms of sulphate of nickel, Ni*SO« + 3HH). In all 
tlmt ftrmbini ^^""^ it may be obaorred that pyramids similarly situated between the 



IM 



CRYSTALLOGRAPHY. 

J^. 228. Fiff. 229. 





Fiy. 230. 



Fig. 231. 





iixps fonn combinatioa-edges panillel to the baao, e. g^ oP, jP, P, and Pte . 
00 P 00 {fy, 231), whereas pyrainidB and priams differently situated with repaid to tho 
axes form combination-edffes inclined to tho base, e.g. P and ao P ee , vnfya. 225, 226, 
227, 230, 231 ; also P and Pas mjlgs, 230, 231. This rule ia of great usa in deter- 
mming tb© relations of the faces io complicated combinationa. 

Befmlliedral Fiimui* A aquare pyramid may become hemihedral in the i 



manner as a regular octahedron (p. 128)^ via* by the extension of four alternate fa^M 
till the others are obliterated. The figuro thus produced, chilled a quadratic sphe- 
noid, ifl a four-sided pyramid disdngiiiahed from the regniiir tetraheflrtin by the form 
of ita facea^ which ar« not eqiiilat€ral but isosceles triangles. The prLncipal axis ter- 
minates in the middle pointa of two of tho <?djjea (terminal edges) ; the se^wndary axes 
in the middle points of tho four other edgva (lateral edges), A quadratic aphenojfd is 

denoted by the symbol *^ or — =— , according to that of the pyramid from whicli it 

is formed, Tho signs + and — prefixed to these symbols have tho same meanings 
as in the case of the regular tetrahedron (p. 128). 

Sphenoids rarely occur alone ; a solution of cyanide of mercury, howover, sometimes 

yields by spontaneous eraporation perfectly developed sphenoids in which - — 985. 

More frequently sphenoids occur in combination, g.^. with tlieir tfirminol edges trun- 

p 
cated by the face oP, and their lateral edges by ooP », The eummita of - may 

also he replaced by the faces of the opposite sphenoid, in which case they are dis- 
tinguished as + ^ and — ^. A combination of these two forms equally develope<l 



2 2' 

has the external form of a square pyramid, but may generally be distinguished 
therefrom by the different modificatioiia of ita edges and Bummits, Fig. 232 is a form of 

copper-pyrit^ss^ consisting of a sphenoid + ^ having ita 

terminal edges replaced by oP, ita summifca by fac«a of 

— , while those combination-odges of the two sphenolids 

which are situated like the terminal edges of P, are tniu- 
catcd by faces belonging to tho pyramid P oo. ModiJied 
sphenoids also occur in cyanide of mercury, format*? of 
strontium, cholalie acid, 6cc. ; but they aro not common. 
•JUiPrt 

Another hemihedral form — ^^ i* prodnced by tho 

growth of the alternate faces of the octagonal pyramid 
{fy. 216). It is a double pyramid with a square base, 
hut having the itides of the base obliquely inclined to the secondary axes, as may be seen 
by prolonging the alternate aidaa of the octagon {fy. 216) till they meet Such a 





HEXAGONAL SYSTEM. 



137 



form 18 called a square pyramid of the third order. Id like manner are formed 

square prisms of the third order. Square pyramids of the third order never 

occur alone, and bat rarely in combination. Examples are found in tungstate of lead, 

tungstate of calcium, and a few other minerals. In native tungstate of calcium 

4P2 
(Scheelite) the primary form P occurs, modified by the faces 2P oo and -^r-. 

Bexaffonal Bystenu 

JShombohedral, Monotrimeiric System {Drci- find eiruixiges^ sechaglUdrigeSj drd" und 
drdgliedriges System). — Ciystals of this system have three equal secondary axes 
situated in the same plane and inclined to one another at 60^^, and a principal axis 
at li^t angles to the plane of the secondary axes. If this axis be placed vertically, 
the crystal appears differently developed in the vertical and horizontal directions, but 
equally and similarly developed in the six directions lying in the horizontal plime, 
viz. at the six extremities of the three secondary axes. 

The principal axis is sometimes longer, sometimes shorter than the secondary axes. 
Its length c is expressed by referring it to that of a secondary axis as unity. 

As three points determine a plane, the position of any face of a crystal in this i^tem 
is determined by the distances from the centre at which it cuts the principal axis and 
two of the secondary axes. The most general form is one in which each face cuts two 
of the secondary axes at unequal distances. Suppose, for example, these distances 
to be to one another as 1 : f . Draw three horizontal axes cutting one another at 60^, 
as in fy. 23S, and set off on two of them the distances a, |a. Then, by a construction 
similar to that described at p. 133, it is found that the horizontal section of the re- 
quired form is an equilateral dodecagon; und by joining the angular points of this 
polygon with the extremities of the principal axis (supposed perpendicular to the plane 

Fig. 234. 



>x« 





^1^. 235. 



M 

of the paper) we obtain the symmetrical double twelve-sided pyramid (Jig. 234), bounded 
by twenty-four scalene triangles A B C, six of the basal summits, B, being situated at 
the extremities of the secondary axes, and six 
others, C, half way between. Such forms occur in 
combination, but not singly. 

The genend formula of the solid thus determined 
is a :na: pa: Ct ia which when n is given, p is 
determined. In the preceding figure, where n — f , 
p is found to be equal to 3. There are two 
particular cases of special importance : — 

1. When « a» 1, or the formula becomes a:a:pa:c. 
In this case it is easy to see that the twelve 
sides of the base are reduced to six, and the base 
becomes a rogular hexagon (Jig. 236), having its 
angles at the extremities of the secondary axes. 
Each side meets two contiguous axes at equal 
distances, as at /, k, and is parallel to the 
third, so that p « », and the formula becomes 
« : a : 00 a : c. The form thus determined is a 
double six-nded pyramid {fig, 236) bounded by twelve isosceles triangles ABB, which 




A-C*^."-^ 



/ 



138 



CRYSTAIiLOGBAPHY. 
F^. 236. -%. 2Sr. 





are acnte- or obtnie-angled, accordLng to the ratio of tha principal to the eecondaiy 
ax«fi. Every section perpendicular to the vertical axis ia ^ regular hexagon, like 
the base, and every vertical Bcction paaaiiig through the principal axis in a rhotnbus. 

2. Wlicn n *■ 2. Eiich fuco cats ono of the iK.'Condarj axes at the diBtance a and 
another at 2a, In this caae the construction in Ji^, 235 fihows that the hase of the figure 
IB a regnki hexagon, having iU sides in the nituation of the dotted linee of the figure, 
each side paaaing through one of the angles of the former hexagon, and cutting the 
third secondaiy axis also at the distance *2a from the centre, «o that the formula be- 
eomai a :2a: 2a: c. The solid figure obtained hy joining the angnlaj pointa of this 
hexagon vith tlie ends of the principal axis is also a double aix-aidcd pjTamid, like 
fy. 236, but differcndj situated^ the coda of the secondary axee passing through the 
middle points of the sides of the hexagon, and the basal summits C baing aituated 
halfway between these axes (fy. 237). 

Whea two or more hexagonal pyramids occur together in the same crystal, one 
replacing the edges or summits of the othert one of them is usisumed as the primary 
form, the secondary axes being supposed to pa^sd through the angles of its base ; and 
of the rest, those which are simQarly sitnatea with regard to the axes are called acuter 
orobtuser pyramids of the first order, while those which are intermediately 
situated, that is to say* having the middle points of their bnsal etiges at the extremities 
of the axes, are called pyramids of the second order. The relative lengths of 
the priucipal axe* of these pjTamids are denoted, as in the dimetnc system, br placing 
a multipUcr m before the sign of the principal axis. The abbreviated symbols of the 
several pyramids are also similar to those used in the dime^c system ; thus i-^ 



Primary form . 
Pyramids of the first order 
Pyramids of the second order 
iJodecagonal pyramids 



a : a * ooa : a » P 
a : a: Qua: me ^ wiP 
a:%a: 2a :me ~ mP2 
a:na: fa :mc — inBn 



If in either of these formulae m e^ D, the pyramid is reduced ta a terminal face oP 
parallel to the plane of the secondary axes, 

Jf m = 00, m either of the formula, the corresponding pyramid becomes a vertical 
prism, coP, odP2, or odP«^ of indefinite length. 

These prisms and the terminal faces, being nncloaed forms^ can only occur in com* 
bi nation. 

The terms^ next obtuserand next acnter pyramid, are used in this system in the same 
sense as in the dimetric system (p, 134) ^-^fl. The next obtnser pyramidisthat 
whoso faces have the same situation and inclination relatively to the principal axis as 
the terminitl edges of the primary form. For the primary form P, or a : a : od a : (? 
iJUf. 236), the next obtuaer pyramid is evidently a: 2a:2o:c or P2 {Ji^, 236); and 
generally^ for exery hexagonal pyramid wP, the next obtnser pyramid is ?7iP2. 

6. The next acuter pyramid for the primary form P, is that whoae terminal 
edges have the same position and inclination relatively to the principal axis as the 
faces of the primary form. The base of the primary form being the fuli-lined hexagou 
{^fig. 236), the next acuter pyramid is that whose faeea meet the principal axis at the 
same distance c from the centre, and pa^s through h, if, the middle points of the aides 
c^, kfj and the correfl|>onding pointa of the other sides of the same hexagon. Now 
the lino bd cnta the axis <7A' in the point t, so situated that gi = a gk% CoDiie<juently» 
the formula of this pyramid is | o : 2 , ^ : 2 . Ja : tr. or o : 2a: 2a : |<7 = |P2 : and gene- 
rally, for every pyramid of the first order ^iP, the corresponding next acuter pyramid 
is |/7iP2. The terminal edges of a pyramid of the first order wP are symmetrically 
truncated by the faces of a pyramid of the second order otP2, 

The hexagonal and dodecagonal pyramids and piisms above described^ are the only 



HEXAGONAL SYSTEM. 



139 



bololieclral fonm of ihe hexagonal system. The dbsed forms (the pyramids) are 
rarelj found alone; examples of simple hexagonal pyramids are found in the com- 
pound of grape-ffngar and diloride of sodium, and occasionally^ in quarts. The un- 
closed forms, vis. the prisms and the terminal fiices, occur only in comhination. 

OomliliiatlABS of tbe Bolobedral forms of the Hexagonal Byatem. 
Hexaeonal pyramids and prisms combine together in the same manner as the corre- 
sponding figures of the dime^c system. When two pyramids of the same order occur 
together, the obtuser of the two acuminates the summits of the more acute, just as 
in fy. 220 (p. 134). In like manner, the hexagonal ^rism occurs acuminated by the 
pyrainid of toe same order, the faces of the latter resting on those of the prism, and 
fomaing horizontal combination-edges, as in quartz (fy. 238). When hexagonal pyra- 
mids of different orders occur together, the faces of the one replace the edges and 
summits of the other, producing truncations, bevellings, or acuminations, according to 
their relatiye positions and inclinations. Examples of these combinations, together 
with the terminal £Eu;e oP, are seen in^«. 23G, 241, 242, which are forms of apatite, 
and^. 240, which is a form of beryl. 



^.288. 



F^. 239. 



i^. 240. 



i I 

I i 

C i 

I I 

^^. * — ■ — ■ „™„^-^. 

xX ^^-: — ^ 



^f?^ 




The forms oo P and oP combined together produce a yertical hexagonal prism with 
horizontal end-fiices. When oP predominates, the prism is reduced to a hexagonal 
tablet In fig, 240 the combination-edges of this form are truncated by the faces P 
bdonging to a pyramid of the same order as the prism ; in fi^, 241 the combination- 
summits of the same form arc truncated by the faces of a pyramid 2P2 of different order. 
Fig. 242 affords a good example of the manner in which the different forms making 
np a complicated combination may be determined. The pyramid whose faces are 



Fig, 241. 



Fig, 242. 



Z ^ ' Y^"^ 



z: 



"V 




denoted by P is chosen as the primary form, because it is the one to which the other 
forms may be most conycniently referred. The relation of the faces oP, oo P, oo P2 to 
this primary form is obyious. The faces of the next obtuser pyramid P2 are known 
because they truncate symmetrically the terminal edges of P ; those of 2P2, because 
they truncate the combination-summits of oP and oo P (as in^. 241), forming com- 
bination-edges which are parallel to the terminal edges of P (or the combination-edges 
between P and P2) ; and those of 2P, because their terminal edges are symmetrically 
tnmcsted by 2P2. • 



140 



CRYSTALLOGRAPHY. 



Fig. 243. 




%=^^ 



Symmetrical twelve-sided pyramids rarely occur in comliiiiAtioD, with all theic 
faces. An eiarople of guch a eombination is.howevePj fotmd in beryl {fg> 243), m 
wliich tlie twenty^four faces of 3P| (denoted in the figure Ly 
z) truncate the edg<?s between 2P2 and mV, 

In all combinations of heiagoDal (and likewise of qnndratic 
forms, tho following rule holds good: ---Fonns which lie in 
the tams direcHon between the secondary axes interaect one 
anothet'in horizontal edgcs^ or in such a mannur that the 
ttpfer and lower combination-edges are paralid to each other ; 
hut forms which are dissimilaritf sitmited hetwBptt the 
secondary axes^ intersect one another in inclined edges, the 
npper and tower not being parallel, Thna the combination- 
radges between oP, P, 2P ami ooP (Jt^. 242) are all parallel, 
an also are those between OP (which is the same as oP2), P2, 
2P2 and m P2 ; whereas the combination-edgea between P 
mid 2P2, or 2P2 and ooP in the same flgura^ or between 
3P &nd ooP 'm/ig. 243 are not parallel to one another. 

Bemltiedral fomittii The hemiliedral forms of the hexagonal sj'stem octmr more 
frrqut^ntly than the holohediul forms, and among them there are two of especiid iirt- 
portaece^ the Rhombohedron derived from the hexagonal pyramid, and the Seal e- 
nohedron derived from the dodecagon al pyramid. 

1, Ehomhohidrons. — Suppose that in a hejcogonal pyramid (of the first erder^ Jig. 

238) the front face above^ the right and left faces below^ and the three faces alternating 

with tbese, are erteeded till they obliterat* the intermediate fac^, viz. the frout below, 

the riglit and left above, &c. ; the postilt will ba the rhombohedron (jSy. 244), a 

fltrure bounded by six rhombuses. It has eight summitH, which are of two kinds, vhs. two 

terminal Huinmits A A, formed by the meeting of three tenninal edges, and six lat^^nil 

gummits D D, formed by the concnrrenco of two lateral edges and one terminal edge. 

Of the twelve edges, six are terminal, extending from the terminal to tlie lateral 

snmmita, and six iateral* extending in a zig-sagline between the lateral samroiti. The 

principal DJtia joins the terminal summits; the seooudaij axes unite the middle points 

of every two opposite lateral edges- The symbol of the rhombohedron would, ac- 

P 
cording to general iisage, be ^ , hut it is usually rephiced by the shorter Bymbol E, 

In the rhombohedron formed as above described, one face extands from above for- 
wards, and one edge from below forwards ; if however tJie other alternate faces of the 
hexagonal prism (Jig* 23&) be supposed to grow, viz. the right and leffc above^ the 
front below, &c., the result will be a rhombohedron in the opposite position, that is to 
iiry, ImTi&g an ^g& extending from above forwards and a face from below forwards. 

Fig. 246. 





as in Jig. 246. When these opposite rhombohedroiis oocnr together in the same 
crysttd, their faces are distingm'shod by the signs + and ~, the first described rhom- 
bohedron, which bos a face extending ftt>m above forwards, being usually denoted by 
->- R, the opposite one by — R. 

Rhombohedrona are acute or obtase, according as their terminal edges and fiices 
intersect one another at acnt<? or obtuse angle,?, these inclinations depending of course 
upon the ratio between the principal and secondary axes. For a particular ralue of 
this ratio, the faces and edges meet at right angles, and the rhombohedron has the 
form of a cube. It is not, however, identical mth a cube in anything but external 
shape ! for its edges and summits are of two kiuds, and the terminal edges or summits 
may be modified, while the lateral edges or summits are not, and vice versd^ whereas 
in the cube, if any modification occurs, aU the corresponding parts mast bo similarly 
modi lied. 
When A number ^f rhombohedrons of diJfereot degrees of acnteness oceor together* 




HEXAGONAL SYSTEM. HI 

that one is selected as the primary form in the direction of whose faces the crystal 
cleaves most easily, and this rhombohedron being denoted by + K (tiat is to say, being 
so placed that one face of the primary form extends from above forwards), the others 
are denoted by + mR, the nnmber m denoting the ratio of the principal axis of each 
rhombohedron to that of the primary form. This ratio is ^ways very simple. (See 
Caixspab, i. 721.) 

When two phombohedrons of the same order occur together, the more obtnse 
acuminates the terminal summits of the more acute, as in fy. 246, a form of calcspar 
in which the terminal summits of + 4R are acuminated by + R ; but when rhombo- 
hedrons of different orders occur together, the edges or summits of the one are trun- 
cated by the faces of the other, as in Jigs. 247 — 249. A rhombohedron by which the 
terminal edges of the primary form are symmetrically truncated, is called the next 

Fig. 246. Fig, 247. Fig. 248. Fig. 249. 




obtuser rhombohedron of that form; and the rhombohedron whose terminal 
edges are symmetrically truncated by the faces of the primary form is called the 
next acuter rhombohedron of that form._ Of any rhombohedron + wiR, the 
next obtuser is + ImRt and the next acuter is + 2^R. In^. 249, + R is the next 
obtuser rhombohedron of — 2R. Examples of rhombohedrons thus related are found 
in calcspar (L 721), also in chabasite (i. 843). 

The two opposite rhombohedrons + R and ~ R, formed from the same hexagonal 
pyramid, are often combined together, and when they are equally developed, produce a 
combination undistinguishable in form from the holohedral hexagonal pyramid. There 
are, however, essential diflTerences between the two : sometimes the faces of the opposite 
rhombohedrons differ in lustre or in mode of striation ; sometimes the crystal cleaves 
in directions parallel to one set of faces and not to the other ; frequently also the 
manner in which the faces and edges are modified affords the means of distinction : 
thus the horizontal combination-edges of quartz, oo P . P (Jig. 238), are sometimes 
truncated by the faces 3P ; but this modification does not affect the whole of these 
edges, but only the alternate ones, e. g. the front combination-edge above, the right 
and left below, &c, whereas, if the crystal were holohedral, all these edges would be 
modified alike (Jio. 258). 

The terminal &ce oR truncates the terminal summits of a rhombohedron, as in 
corundum (Jig. 146, p. 86) ; if the face oR predominates greatly, the crystal is 
reduced to a tablet like^. 147. 

The more the principal axis of a rhombohedron increases relatively to the secondary 
axes, the smaller do the angles at the terminal edges become, and tne more nearly do 
those of the lateral edges approach to 120°, that is to say, to the inclination of the 
fares of a hexagonal prism (see Table, vol. i. p. 721). And finally, if the principal 
axis becomes infinite, the facps of the rhombohedron become parallel to it, and the 
figure becomes a hexagonal prism identical with oo P ; in rhombohedral combinations 
it is however denoted by oo R. 

Rhombohedrons occur in combination with hexagonal prisms. With a predominant 
hexagonal prism of the first order, ooP, or ooR, a rhombohedron (of either order) 
combines in such a manner as to produce three-faced terminations, the acumination-faces 
resting symmetrically on the faces of the prism, and disposed alternately above and 
below, as in calcspar oo R. — }R (Jig. 260) ; on a prism of the second order, ooP2, a 
rhombohedron likewise forms three-faced acuminalions, with its faces likewise disposed 
alternately above and below, but resting symmetrically on the edges of the prism, 
as in Jig. 251, which is a form of dioptase. 

2. Scalenohedrons. — This form, represented mjias. 262, 253, is produced by the 
extension of the alternate faces of the double twelve-sided pyramid, Jig. 234, p. 137. It 
is bounded by twelve scalene triangles, has two six-faced terminal summits, six four- 
fiiced lateral summits, and eighteen edges of three different kinds, viz. six longer and six 
shorter edges between the terminal and lateral summits, and six lateral edges forming 



142 



CRYSTALLOGRAPHY. 
Fig. 260. Fig. 251, 



r^iT 




* 




; 


t^. 


• 


/ 



a iigitg betwoan the lateral stttnoiits. The middle points of tlie«a lateral edges are 
sitimtedftt the extremities of tiie secondary axea, bo that the«e edgea haye the same rela- 
tive situdtiou as the lateral edges of si rbombohedron \ and in fact, the easiest way of 
conceiving the gooeration of a jBcalenohedron ia to eappose the principal aiia of a 
rhomlMjhedron to be elongated, and straight lines drawn from the ejctremitiea of thin 
elongated axis to the latcriil summits of tJie rhoiabohedroD. 

A scAlenohedroQ is determined bjthe dimensloDS and position of therhombohedjoa 
from which it may be coneeired to bo formed, and by the number of times that tho 
axis of that rhombohedroB must be multiplied to produce it; the latter is indicated 
by placing a auporior figiiro to tbo right of the symbol of the rhombohedfon ; thus a 
Bcaldtohedron whodo Tertieal axis is n times that of ita generating rhombohedrou mlt, 
IB denoted by the aymbol ^i". 

Fig. n% Fig, 253* 





Scalonohedrons are further distinguiflhed as + <5r — , according to the position or 
order of the generating rhombohedron, or according as they are produced by the 
DxtenflioQ of one or the other aet of alternate faces of the primitiTe do<leeagonal pyra- 
mid. The op|^Cl«ite forms are ahown in Jigt. 252, 263. Tho form + E" occurs in 
colcMpar, conatitntiug the variety called i<^A-^Uoih spar {Jig. 123, vol i. p. 722), 

The terminal summits of a scalenohedron are often acuminated with three faces of 
tho rhombohedion from which the scalenohedron may be supposed to be deriTed* the 
combination-edgea being parallel to the lateral edges of the scalenohedron, aa in 
Jiff. 264, which is also a form of calcepar. Tho lateral summits ajo also frequoutiy 
trttncated by the faces of the first hexagonal pyramid os P, and the bteral edges by 
those of the second hexagonal prism cmV'l. 

3, Other henuhedral Jhrim. — The double dodecagonal pjrramid 7nl*n {Jig. 232) may 
become hemihedral in the same manner as the double eight-aidedpriam of the (quadratic 
ijyetem (p, 133), ti^. by the ext^>uaion of each jiltemuto pair of faces meeting in a 
lateral tslge* The figure thus produced ia a double Bix-aidedprism of the third 
order. Evi'ry dodeeagoual pyramid yields two such hexagonal pyramids of the third 
order, according as one or other set of altcrDato fiices U supposed to grow. The base 



HEXAGONAL SYSTEM. 



143 





of one of these pyramidB is represented by the full lines in {fy. 266\ that of the 
other bj the dotted lines. The lateral summits of each of these pyramids are situated 
between the secondary axes, and at unequal distances from each pair of axes. 

Hexagonal prisms of the third order, — —, are produced in like manner 

fiom the dodeeagonal prism. 

This kind of hemihediy is strikingly exhibited in apatite. Jn fig. 2il (p. 139) tfao 
eombination-edge, which each £bu» <^ 2P2 forms with the two conti^ous faces of ooP, 
may be truncated by a face of a dodecagoniJ pyramid, as in beryl {Jig, 243, p. 140), 
iriiere the twenty-four small fiices denoted by z belong to the pyramid 3P|. In apatite, 
howeyer, only half of these combination-edges are thus truncated, viz. those which each 
fiice 2P2 fi>nns with the £Me oo P to the left of it, while the one to the ri^ht remains 
unaltered (Jg, 266). The truncation-faces, therefore (represented hyminfig. 266), 
3p3 

In like manner, of the two combination-edges 



belong to the hemihedral form • 
^.256. 



Fig. 267. 



Fig. 258, 




whidi eaeh fSice aoP2 forms with the two contiguous fiices ooP (fig. 242), one only is 

a)P' 

truncated, the &ee6 p (fig. 266) belonging to the hexagonal prism— ;^. 

The hexagonal Dyramid of the second order(j^. 138) may also become hemihedral bythe 
obUteration of half of its &ces in the manner just described, the resulting figure Ming 

4nP2 
a double trianglar pyramid — ^, having an equilateral triangle for its base. It nerer 

occurs alone, but is found in quartz, replacing half of the summitff formed by the fiices 
of the two opposite and equally developed rhombohedrons + R and — R (p. 140) and 
the hexagonal prism oo R If the crystal were holohedral, the whole of these summits 
would be thus replaced, and the combination would be that represented in fig. 267, 
iHiere tha fiMSS x belong to the second hexagonal pyramid 2P2. In reality, however, 

only half these Misimits an thus repkced, as represented by the faces x or -^ in 
fig, 266. 



144 



CRTSTALLOGRArnY. 




HaHgODiil prisms of the second order likewise becom p hcmihedral b}^ tlie oblitertttion 
of liftif their fttCo« altemAtdj dtiiiited, producing triangular prisma. 

Tttartohtdry. — Qnarte ftlTords a remarkftbre exampb of a combination in which 
only ono-fourtb of the possiblo facta are prcaedt (p. 121). The combination -edges 
between the faces x and ccR are often truncated by faces y, belonging to a dodecagonal 
pjT&midj 6PJ ; but of the twenty-fonr faces belonging to this form, six dtlTore preficnt, 
aa thown in fy. 258, Quartz lUEewlae exhibita other forms of tetartobeorol develop- 
ment. 

Trlmetrte or Atiomlile Syitem* 

Prismatic^ Right pri^math, Orthotypic^ Isodink^ Rohhedm-rhombotrimetric System 
(ZiiW- und twdgtiedrigcM^ tin' und eifiarigcM System), 

CrystalH belonging to this fijstem haTO tluee rectangular axes, aE of different 
lengths ; in other words, they are unequally deTeloped jn three dixectionfl at right 
Anglos to each other. The axes are HkewiM dissimilar in this respect, that tbey ter- 
minate in dissimilar parts of the crjstal. 

The three axes of a trimetric ciystal are therefore ein gti 1 a r ax es (p. 120), and there 
is no reason for considering either of them as a principal axis rather tban the others* 
It is, howe¥er» convenient to regard as the principal nxis, 
that one of the three in the direction of which the crystal is 
to the greatest extent prism atically deyeloped, or to which 
the greatest number of &ce« are parallel. This iixis we sUjiU 
suppose to be placed vertically, and denoted !jy the letter o. 
Of the two secondary axes, the Bhorter, called tho brachy- 
di agonal (a\ will be supposed to extend from left to 
right; the longer, or macrod i agonal (h), from bade to 
front (j^. %Bd\ The relative lengths of the three axes vary 
greatly in different aystals belonging to this system ; in 
sulphur, the proportion of o : & : ff is 0*81 : 1 : 1*90 ; in neutral 
sulphate of potassium, it is 0*746 : 1 : 0'fi73. 

A plane passing through any two of the axes is called a 

principal section, and is further distinguished as basal 

when it passes through the two sccondmy axes, macrodiagonai when it pjisses 

tbrough the principal and longer secondary axis, braehy diagonal when it passes 

through the principal and shorter secondajy axi^. 

Ffg. 260* Tho most genera)^ and at the same time the simplest form of a 

tri metric crystal, whose faces meet tho axes at the dist<ances a b c 

from the centre is a s^rmmetric eight-sided pyramid * {Jhs. 259, 

2G0), having its summits at the extremities of the axes. Its faces 

are all Hcalene triacglcs. Its twelve edges are of three kinds, viz, 

four lateral edges, B C, situated in the basal principal section, 

four terminal edges, A C, in the macrodiagonai, and four terminal 

edges, A B, in the bmohydiagonal principal sejition. All the 

three principal sections are rhombuses, but with different angles. 

Ilcnce this form is called a rhombic pyramid. The six summits 

are also of tliree kinds, viz. two terminal stimmits, A, two lateral 

summits, B, at the extremities of the brachydiagonal^ and two 

lateral summits, C, dissimilar to the latter, at the extremities of 

the macrodiaeonaL 

The gener^ symbol of a rhombic pyramid is t 

a : i : c, or P, 

The particuiar form varies witli the ratios between the axes. 
When two or more rhombic pyramids occur together in the 
same czystal, they are distinguished by symbols similar to those 
nscd in the prece<ling systems. 
If the secondary axes remain the same and the principal axis varies, the formula 
becomes : 

a : b : ww?, or j?iP, 

• It If Imiwrlanl to ctiterve how the irtt«rpreUtion of a cry»Ul!o(rrApki!c fonnwk rmrtet Mccordins to 
the law of lymmptry of the crjutal, ih«tt ■• to ♦«!, accordlnFE to Ih*- »j«.'ni to which It belougi. In tti« 
trlmeiric tTiKMii. th«» fonnuU d : 6 : c r<»prp*<^nti a figure with only eljrbt sLlps, one In cftch octint, 
b«e«Ufe thedlmen»ioni of the crytUl behiff dlfferpnt !n th<* dlreriion* of all three iiet, mch of ihn 
diftano^ a, b. u, !■ mnwiiTM *lonjr one ax** onlj j hut kn the dimetrlc if item, whGr«e farm* Ar» e^tuiMv 
dereloped tti thedlf«ctJoni of th* two lecondnry axps, e*ch of ihc di«t«ure4 it, 6, mint b* «pt off on eiich 
ortho4i» axes, whmce t1ier« retults a flgtjr* hariii^ iwlce the fir<w?iHlirin iiMmher of fac<"», that U to Mf, 
tixtd-n (B 133) I and fn the mnrtotrn-tric *vHem, which Includfi the fDrra* ef^ually developed In iti* 
din rfi on of 411 ihrr« nxft, thf proccn laii dcscTibt>d has to bo rrpealed three thti»i, resardtng each BaU 
in turu s« a prinripiil axil ; ht-iicc reiuki a Cgurt' having 3 X 1C = <8 tide* (p. JWJ. 




I 




TBIMETRIC SYSTEM. 145 

the pyramid beooming more acate or more obtuse in the vertical direction, according 
uiR is greater or less than 1. 

If the macrodiagonal raries, while the other two axes remain the same, the formula 
becomes: 

a : nb : c, or f n. 

and if the principal axis Tazies at the same time : 

a : nb : mc, or mPtif 

vhich represents pyramids more or less elongated in the direction of the axis b^ ac- 
eording as it is greater or smaller. In like manner, the yariation of the brachydiagonal 
pTes the forms : 

na : b : mc^ or m^n. 

When m or n becomes^ infinite, the faces become parallel to the principal or one of 
the seoondazy axes, and indefinitely elongated in the corresponding direction. 

a : b : ooc, or ooP 

Rprasents a rhombic prism, whose fiiices meet the secondary axes at the distances ff, b 
from the eentre (these axes forming its diagonals), and extend indefinitely in thedireo- 
tkm of the yertical axes. 

a : nb : oo c, or oo Pfi , 
and na : b : oo c, or oo tn 

likewise represent indefinite vertical prisms, but with dififerent horizontal sections 
a : cob I mc, or mPco 

represents, in like manner, a series of prisms whose faces are parallel to the macrodia- 
gonal, and whose sections perpendicular to that axis are rhombuses, having a and nuf 
lor their diagonals. 

Qoa : b : me, or mPco 

Kpresents a series of prisms whose faces extend indefinitely parallel to the brachydia- 
gonal, and whose sections perpendicular to that axis are rhombuses, having b and m o 
tar their diagonals. 

The prisms mPoo and fTtFoo , whose faces are parallel to one of the secondary axes, 
ue called domes (from domua, a house), because they terminate the crystal in the 
Tertical direction like pitched roo& {see Jigs. 266 — 268), and are further distinguished 
IS macrodiagonal orbrachydiagonal domes, according to the direction in which 
they extend. The formula 

a : cob \ ooe, or oo^oo 

xfpre^ents a pair of indefinitely extended planes passing through the extremities of the 
mchydiagonal, and at right angles thereto^ or parallel to the macrodiagonal section ; 
iDd 

00 a : b : oo c, or oo f oo 

represents, in like manner, a pair of infinitely extended planes parallel to the brachy- 
diagonal section, and passing through the extremities of the macrodiagonal 

When c «B o (whatever may be the lengths of the secondary axes), the form is ro- 
dneed to a single plane, the terminal face oP, parallel to the basal section. 

The prisms and the terminal planes, being unclosed forms, occur only in combination. 

The following table* exhibits a summary of all the forms of the trimetric system 

* TIm formni* abor^ given for tbfc and the preceding ijrstemi are those originallj proposed by Nau- 
laaa andadoptod bj Koppaad many other writers. Dana uses similar formulse.but shortens them bjr 
Tirssiim th« P.aod czpreislnf infinity by tf or I, instead of od. The primary form a : 6 : c la denoted 



^ 1; the other forma in the manner tliown in the foliowiog table ^ 



P - I 

esP s m 

»P a I 

mN = m% 

mrn a mS 

es^oB a fffi 

mP at = f//l 

•goo a it 

odPod a a 

Op a 

TW «orra»inna used to the monometric, dimetric. and hexagonal systems are of similar charact<>r. 
TWae formulsr are certainly shorter than those of Naumunn, and the P In the latter (or the O in the 
■seosDecrtc af stem) does not add much to the senie; but on the other hand.Naumaan's formuls strike 
tkt ere bHter and are more distinct from anything else in the text than the shorter formal* of Dana. 
[For thr mode of rcprceeotatioo adopted by A 1 1 ler, see the new edition of PkitUp$*» Mineraiog]f, by 
w!j^^!SoilW.H. Miller. Lbndon.iMl] ^ 

VoL.II. L 



146 



CRYSTALLOGRAPHY. 





m< I 




IM>1 


oPoD 5^ oP 


P^ 


foo 


mPoo 


oP« = oF 


mPn 


Pn 


ml»» 


oP 


«tP 


3 


«*P 


oPji = oP 


mPn 


fn 




ot*ao - 0^ 


iPpao 


too 



[m denotes n multiplier Taiymg in magnitude from to co; n a multiplier raryiiig 
from 1 to t» ] : — 

lrt< I IM>1 

00 Pod 

ooP 

oofgo 

Com'blDaUoiLB. The pyramids, pnsms* domes, and end-faces of the triraetric system 
form u large nuruLer of combinations, of wHch the foUoving may be regardod as tlio 
most important. 

The terminal edges of the primary form are acuminated l>y tbo&e of an obtnawr 
pyramid of equal base, the combination -edges being parallel to the lateral edges of the 
primary fonn^, as in^^. 26 1^ which ia a form of sulphur* The brachy diagonal dome 
Poo tnmcates aymmetrically the mocrodiogonal terminal eilgea (fy, 262), and in liko 
manner, the macrodiagonal dome Pm produces symmetricid truncation of the bracliy- 
diagonal terminal edgea, the combination-edges being in both c&sea parallel to each 
other* Acatcr and obt user domes (tinPflo or «iPao , for which if»* 1) would likewise 
replace the terminal edges wholly or partially » the combination-edgoa eonreiiging 
towards the terminal snmmita when the dome is mora acute than the primary from 
(m > 1), and diTei^ing in the contraty en»r: 

The teirminal summits of the primflry form are tmneated by the baaal end-faces oP 
(Jtff. 262) ; the macrodiagftnal summits by the bracby diagonal end-faces co^oo ; and 
the brachydiagonal summit-s by tJie macrodiagonal end-faces ocf'as . If the«e two 
p>iirs of end-faces predominate together with t£e primary fofnij the reaidt ia a combi- 
nation like fy. 263, a form of uranic nitrate. 



%. 26L 



Ft^, 262. 



Fi^. 263. 






The lateral edges of the primary form are symmetrically truncated by the prism 
00 P having the name basti or secondar^r axes ; if the latter predominates^ the pyramid 
P forms 4-facod summitd to it, tJio combination-edges being parallel to the base and 
to each other, as in snlphateof rinc (fia, 264) i but in the combination of a prism and 
apTtamid baring diBerent bases {i. e, nariog their aeeondaiy axes in different ratio to 
caeh other), tbeeorabimition edges are inclined to one another, as in^^, 27 1| a form of 
sulphate of potosaium, which eibibits the combination of P with citP2. 

The eilgea of a prism in which tho macrodiagonal terminates (the acuter edges in 
00 P) are truncated by the brachydiagonal end -faces wPoo, and the brachydiagonal 
edges by the macrodiagonal end-fac^^s ooi^oo {fy. 276). The acut43r edges of tbe 

ism, oDp are berelled oy the faces of a prism aaPn of different transTerse section 
^e. g. by 130^2, in/<^. 265, a form of topaz), in which it may also bo observed that the 
JormsP and wP, whieh have the same base, form parallel combination-e<lge8 ; whereas 
P and ocP2, which hare different bases, form combination-edges inclined to eacli other. 
In like manner, the obtuse angles of »P are bevelled by a prism ccPn of different hori- 
eontal section. 

The prism ooP is symmetrieidly truncated at the end by oP, and it is bevelled by 
a bnichyiliagonnl or macrodiagonal dome; the bcTelling faces formed by the nmcro- 
diagonal dome real on the prismatic edges in which tbe brachydiagonal terminates, as 
in ji^f. 266, whicb reprea<*nt* formate of barium ; and the bpTelling faces formed by a 
bnicliy diagonal tlome rest nu the priBmatic edges in which the macrodiagonal termi- 
nates, as in acid nialate of calcium {Jf^. 267). 



pri 
foi 




TBIMETRTC SYSTEM. 

^•7- 264. Fig, 266. 



147 



•p 



•P; 



^=^^ 




The edges of ooP may also be replaced by end-faces, on which the berelling-facos of 
the dome then rest Seyeral domes of the same kind may also oocnr together, as in 
jSf. 26«, a form of nitre, exhibiting the fiices ooP, oof oo , 2f oo , Poo , P. 

In selecting the i>riniaz7 form and the principal axis of a complicated trimetric com- 
bination, the following considerations must be taken into account When pyramidal 
and prismatic faces occur together, the pyramid is regarded as the primary fornu When 



Fig. 266. 



Fig. 267. 



Fig. 268. 




Sw ••••...p« . 




MTcral pyramids occur together, the most predominant is regarded as the primary 
form, unless the ^rcat^^r number of faces can be more conyeniently referred to one ot 
the other pyramids. When trimetric crystals are bounded only by prismatic and 
dome-fiioes, the predominant fEu:es are regf^ed as belonging to the pnsm or the domes 
which hare the simplest formula ( odP, I^oo , or I^oo \ and the axes of the primary form 
an determined accordingly. 

It has already been observed that the principal axis in a trimetric crystal is merely 
Rlatire, not absolute, as in the dimetric and hexagonal systems, and that the axis in 
the direction of which the crystal is most developed, or to which the greater number of 
cdfECfl ar« parallel, is usually regarded as the pnncipaL When crystals are partially 
imbedded in a matrix, or attached to its surface, the most complet^y deyeloped extre- 
mity is usually regarded as the upper, and the axes are determined accordingly. 
When a crystal exhibits only one set of pyramidal faces, these are regarded as primary, 
and the two axes which are most neany equal are regarded as the secondary axes. 
If a oystal exhibits only one pyramid and one kind of end-face, the axes are chosen 
so that these faces may be represented bv oP ; if it has two kinds of end-face besides 
the pyramid, it will appear symmetrically placed if one kind of end-face is regarded 
u od'J^ od, the other as oof oo. 

When a trimetric crystal exhibits prismatic faces, the axis to which these faces are 
parallel is usually regarded as the principal ; if it has prismatic faces parallel to several 
axes, that ■^»« is chosen as the principal in the direction of which the faces are most 
developed. This rule may often appear of uncertain application, because different 
cmrtalsflf the same substance may be most developed in different directions ; but 
vicn the eboioe of a principal axis has once been made^itmust be maintained through- 

l2 



148 



CEYSTALLOG RAPH Y. 



out ihc description of tlio crystal, howoTOP much particular modificatioM may be 
t3eTclope<l io other directions, 

'The following nrf exaiiiplt^s of the determination of somewliat complicated cryetalB 
bclonja^ing to tho trimetric system. 

Sulphate of pot^sium, K'SO*, exliihitn coomdemhlo variptj of form. The cry &I ills 
exhibit, for tho mo«t port, the most deddr-d prismatic developmMit in the direction 
which, in the following figiures (269 to 276), ie placed Tertically. The primary form is 
a rhomhic pyramid c a be a* {fy* 269), whoso ases, represented hj the dottod lines, are 
in the proportion aih \ e^^ 0'7464 : 1 : 0*5 72 7. Tbia priiuaiy form is often modified by 
th« faces of tho vertical prism oe{*2. The horizontal axes of this prism arc 2a and K 
or» what comes to the Bnme things a and ^b. Two of its fiuses will therefore pofis through 
the points a^ d and a lino d € dmwn through the middle point of Ob, puraUel to 
tho vertical axis.^or at loast will be porallet to planes bo drawn, Jf thej pass exactly 
througli the point fit and JA, they will intersect the faces P in the lincfl a a, a* d^ a f^ 
a f, and will produce a form (j»P - eoP2 e^^ually developed) scarcely dlstingmshable 
from a hexagonal pyramid. That ita fac^are really of two kimia may, however, be 
known from the fact that the faces o©F2 appear Bometimea leas, sometimes mora 
developed in cryst^s of tho Batncsalt, as inj^*. 270, 271. Moreover, tb© &ces oc?2 
in Jiff. 269 are iBOficelcs^ while the &ce8 P ai€ Bcalene triangles ; and of the kue edges 
rd, rff, tc\ &e., lying in the macrodlagonial pnncipul section (which might be taken 
forlatenil edges of a hexagonal prism), two belong to the prism ocfri, and the four 
others are terminal edges of the pyramid T, The former meet at an angle of 112° 
41', the latter at 112^ 22'; the former mny be replaced by clcavage-planGs, the latter 
cannot. Tho twelve edgoa, ea^ca*, da, da\ &t , wliich might bo taken for tho ter» 



Fig, 260. 



%. 270. 





minal edges of a hcicngonal prism arc alfo dissimilar, four, viz, c a„ ca\ c'n, c' a\ 
being terminal edges of P situated in tho brachy diagonal principal section, and tho rest 
combination -edges between P and aoP2, 

In J?^* 272, the maenodiagona! terminal edgea of P are truncated by the faces of a 
priam forming parallel eombination-edgeP, therefore j^oo; and the edges of cpp2, 
through which t[ie macrodiagonal pasties, are truncated hy oof' », The combination 
thns prodncod is very much like* the hexagonal comhinntion ocp , P found in quarts 
(Jiff. 238, p. 139). Were this the onl}' known form of sulphate of potiissium, the axis 
which iu Ji/^, 272 appears as tho bnichy diagonal, would be tidten for the principal axis, 
because it is tho one in which tho crystal exhibits the moat decided prismatic develop- 



f^ff. 271. 



Fiff, 272. 



Fig, 273. 





^ 


r 


1 


>^ 




- 


p- 


« 


W 


--., 

s. 


1 


^ 



meut. This axis is, however, not actually regarded as the principal, because a per* 
fectly similar combination is known, viz. fy. 273 (the same as the preceding without 



I 




TRIMETRIC SYSTEM. 

Fig. 274. Fig, 276. 



149 




•Ft 



o>Ft 







P« ), in which the prismatio faces oof oo , oof 2, parallel to the vertical axia, are by 
&r the most predominant. In fig, 274 the faces oof 2 and f ao predominate, so that 
the P-£aoes become rerj small, but are still lai^e enough to show that the faces of 
the TfTtical prism do not form horizontal combination-edges with them, and conse- 
quently that this prism must hare a different base (or its secondaiy axes in different 
proportions) from V ; also that the predominant brachydiugonal dome forms with P 
eombination-edges parallel to the macrodiagonal section (and to each other), and 
thi-refore that this dome is f oo (not 7/if oo , where m is greater or less than unity). 
The crystal has likewise small triangular faces belonging to a brachydiagonal dome 
moTf'. acute than f oo ; angular measurement shows them to bo 3f <» . 

Lastly in, fig. 275, the primaiy form P is combined with Poo , ooFoo , oof ao which 
faces are easily determined, and two vertical prisms, one of which forms horizontal 
combination-edges with P, and is therefore ooP, while the other cvi^iently comes 
aniler the formula oof w, and is found by angular measurement to be ocf 2. 

A remarkable example of the various directions in which oystals of the same sub- 
stance may be prismatically developed, is afforded by native sulphate of barium, 
Ba^!)*. One of its forms is shown in fig. 276, which exhibits several vertical pris- 
matic £ices ; and as the same faces occur more or less developed in several other forms 
of the same substance, this axis is regarded as the principal Regarding the pyramidal 
£ures P as the primary form, two domes may be observed, which truncate^ symme- 
trically the acute and obtuse edges of P : these domes are therefore f oo and P oo ; but 
the vertical prism whose faces form with P, combination-edges not parallel to each 
other, is a secondary prism of the general form ocf » (where w > 1), because the com- 
bination-edges which it forms with P diverge towards the macrodiagonal principal 
section [a prism ocf w, in which n < 1 would form with P combination-ct^es converging 
tvwanLf tnat section]. ATig^^^**^'' measurement shows that this prism is oof 2. The 
end-face oc f ao is known by the horizontality of its combination-edges with f oo. 
The faces thus determined, oo f 2, oo f oo, f oo, f oo, also occur alone and with various 
doprptfs of relative development, producing crystab* of very different character. The 
£Ke ocf 2 predominates in ;ty. 277 ; f oo in;^. 278 ; f oo in>J^. 279; and accordingly 



Fig. 276. 



Fig. 277. 



Fig. 278. 






T^ 



the combination is prismatically elongated in the direction of the vertical axis in , 
fig. 277, of the brachydiugonal in fig. 278, and of the macrodiagonal in fig. 279. In 



150 



CRYSTALLOGRAPHY. 



ihort, wbicheiTF axis may he cboscn as the principal, cry Btals of the mineral will La 
foand which are prisraaticallj elongated in f np direction of one of the seeoadAry axes. 
Fig, 280 is a combination eimilar to Jig. 27 9| but without oel^go ; the dominant face 



FIff. 279. 



Fi^. 280, 





h ^i» , ai ill fg- 278 ; hut P« is likewise moro dereloped ; oiFS is subordinate aa in 

Tho eboic© of a primary form and principal ams for any mibstance is binding, not 
only for all cpystols of that particular substance, but likewise for all tliat are iaoraor* 
phoiQui with it ; thus tho crystals of cccJestin (Sr'SO*) must be referred to the 



primazT form and principal axis m those of heavy spar (Ba'SO*), althotigh ca^lestin 
generally exhibits a form like ^. 280, prismatieallj elongafetl in the direction of the 
macrodiagOBftl. The adTantago of refemiifj all isomorphous i^ryatals to the same 
primary form and principal axis is, that the corresponding feces are then mofo casilj 
niJide out and exprcastvl by analogous! symbols. 

Kemlliedral Towvm* Ehomblc pyramids^ hy the growth of their alternate faces 



Fig. 281* 



Fig. 282. 




•iP 



^4 



till tho others disappear, gwe rise to rhombic BphenoTde, in the same maimer its 
quadratic prisms pioduce fjuadratic sph^^nords (p. 136)* A rhombic sphenoid la 
bounded by four scalene tnangles, and of its six edged, only the opposite pairs are 
eimilar to each other, 

Ehombic Bphcnoida have hitherto been obserred only m combination. A remazk- 
able instance of such a combination is exhibited in fig* 28 1^ the ordinary form of 
sulphate of magnesium (Mg*SO^ + 7H*0), in which the vertical prism oo P ig termi- 
nated by dome-shaped summits placed in opposite directions above and below. In 
flolphate of zinc (Zn'SO* + 7H*0\ which is isomorphous with sulphate ofmagnesinm* 
boto sets of alternate F-faces appear together^ but developed in diJerent degrees, an in 
fy. 282. 

aconoellnl^ Bwmtemm 

Monodinomeiric, M&jwclinohedral, OMigitf, OhUqm prismaiic^ ClinorhondAc^ Avgitic 
lfy$$em (Zwd'Und cinffii^driafs^ hrmifdrisck-rhambuch^trimetTiache* SysUm), 

The forms of this system have three unwmd axes, like those of tJie rhombic 0jitem» 
but differ from tho latter in having two of tieir axes obliquely inclined to one another, 
while the third is at right angles to the other two. Each of these axes is a singular 



I 





MONOCLINIC SYSTEM. 151 

axiB (p. 120), and therefoM the choice of a principal axiR is to a great extent arbitrary, 
as in the zfaoiDbio syatem ; bat it is nsual to consider one of the oblioue axes as the 
parincipal, because most oystals belonging to the syutom are prismaticafly deyelopod in 
the direction of one of these obUquc axes. Of the two secondary axes, that which is 
obliquely inclined to the principal axis is called the clinodiagonal, and that which 
is perpendicular to the other two, the orthodiagonal. 

In representing monodinic cr^rstals, the secondary axes are supposed to be situated 
in a horizontal plane, the clinodiagonal b b {fig. 283) extending from left to right, the 
orthodiagonal a a firom back to £ront, and the pnn- j^. 

eipal axis e e fiom right above to left below. In this ^*^' ^^\ 

mode of representation, the principal axis and clino- 
diagonal appear of their true relative lengths, and 
at their true inclination ( » 75^ in the fig^) ; but 
the orthodiagonal is fore-shortened and appears ob- 
liqae to the other two axes, though really perpendi- 
cmar. Sections passing through the planes of any two 
axes are called principal sections, as in the pre- ^i 
ceding system, and are distinguished as basal, cli- 
nodiagonal, and orthodiagonal, according to 
the axes through which they pass. 

For erezy monodinic crystal, the ratio of the three 
axes (the length of the chnodiagonal being taken as 
nni^) and the inclination L of the prindpal axis to 
the clinodiagonal, have to be determined by angular 
measurement and calculation. The value of L varies considerably in different crystals ; 
in some it is nearly 90^, while in others it differs considerably therefrom. For ferrous 
sulphate, aibie ^ 0*848 : 1 : 1-267 ; JD » 75^ 40'; for felspar, a.b.c^ 1-519 : 1 : 
0-844; L - 630 63'. 

The primary form in this system is the monodinic pyramid {fig. 283) bounded 
by eig^t scalene triangular faces, which meet the axes at the distances a, 6, c from the 
centre. This, however, is not a simple form, for its faces are of two kinds ; four of them, 
which are opposite to the acute angles of the axial system and meet in the edges A above 
and below, are equal and similar to each other; and the four which are opposite to the 
obtuse angles of the axes and meet in the edges B, are also equal and similar to each 
other, but unequal and dissimilar to the former. These two sets of faces may occur 
in combinations quite independently of each other, and a monodinic crystal may be 
deavable in directions parallel to one set of faces but not to the other. Neither of 
them by itself constitutes a dosed form; but the four faces of either set, if sufficiently 
extended, form an endless prism obliquely inclined to the prindpal axis and the clino- 
diagonal. 

A complete monodinic pyramid has two terminal summits c r, and four lateral 
summits, two at the ends of each secondaiy axis. It has four similar lateral edges D, 
joining the lateral summits, four similar terminal edges C, joining the extremities of 
the prindpal axis and orthodiagonal ; and four other terminal edges joining the ends 
of the prindpal axis and clinodiagonal, the shorter ones, A, being opposite to the acute 
angles of the axes, and the longer, B, opposite to the obtuse angles. 

The primary monodinic pyramid is denoted by the symbol P ; but as its two sets of 
faces are dissimilar, and may occur independently of each other, the four faces meeting 
in the edees A are denoted by + P, ana the four which meet in the edges B by — P ; 
the dosed pyramid containing all the eight faces is + P. 

From this primaiy form, others may bo derived^ as in the rhombic system, by 
variation of the length of cither of the throe axes. The variation of the prindpal 
axis is denoted, as l^ore, by placing before the P a multiplier 971, which may have all 
values from o to 00. The variations of the secondary axes are denoted by pladng 
after the sign P, a number n, which may have all values from 1 to oo, the formula 
being endosed in brackets when the variation refers to the clinodiagonal, not endosed 
when it refers to the orthodiagonal 

m «■ o gives the end-faces oP, which cut the principal axis and are parallel to the 
other two. 

The pyramids mP, acuter or obtnscr than the primary form, according as m > or 
< 1, have the same base as P ; and, like that form, have two sets of faces distinguished 
as -f fliP and — mP. The oblique rhombic prism on the same base as P, has the 
symbol 00 P. 

The pyramids mPn, [fnPnl and the oblique prisms oo Pn, [ ooPn] have rhombic 
bases differing in form from that of P. ^ ^ 

^Hie aymboT ffliPao ] represents a series of clinodiagonal domes, that is to say, 
prisma whose tacea and edges are paralld to the dinodiagonaL [P od] is the dino- 



152 



CRYSTALLOGRAPHY. 



diagonftl domo of tlio prinmry form: it* four faces are siniilai', and its tranBrerie 
aeetioiiB are rliomhtiBea Bimilar to the orfhoniiagonal piindpal aection, caca {Jig, 283), 

mPoo b the BymWl of a series ofortbodiagonal domea, acut« or obtuse^ ae- 
cortling to tlu^ value of w. Tbt> four faces of such a dome an? not idl eluiOar ; two of 
them, which are opposite to the acute angles of the axial sjatem* are distiugaiBhed a« 
•f m P 00 ; the other two, whieh are oppo«ite to the obtuse migltsa of the axml system, 
as — 7» P 00. Either of them maj be present without the other. + P oc is the ortho- 
diagoual dome of the primary form ; its trauB verse sectloiifi are aimil&r to the dino- 
diugoDul prineipal eeetion. 

[ CO Poo] repnedents thtj clinodiagODiil cnd-facei^ which cut the orfhoili agonal 
iind are pindlel to the principal axis and cHuodiagonat ; oe Pao » the orthodiagonal 
eiid-fiice«s which cut the cliuodiagonal and are parallel to the principal axis and ortho* 
diugonal. 

The following is a labuhLr view of the formB of the monoclinic system : 





{m<l) 




oPeo = oP 


± mPoo 


+ P« 


oPjt « oP 


j-mPn 


±P« 


oP 


t«iP 


±P 


[oPw] - oP 
oPoo ] - oP 


+ f »^Pfl] 
[;/iPoo ] 


± [P«] 


[P^] 



(m>l) 
+ mPao 
+ mPn 
± Jn^ 
± [mPnl 



eePoD 
ooPn 

odP 
[oDPn] 
] [ ^^'^ ] 



Comblniitlciiia. The monocHnic system does not include any closed siitaple forma, 
every completely developed cry«tal belonging to it being a ctimbinaliou of dissimilar 
fiioes. Even the monoclinic pymmid, P, is a combination of two ht-mipyraniids, each 
consisting of four faces Bimilar to each other, but diBsimilar lo those of tho other half. 

In monoclinic, na in rhombic crystnK the fbllowing rule is of great m*e in deter- 
mining the relative positions of the faces : Any two facts which cut two of the ares at 
pn^pt^titfHoi dUtanfits from the c^itr^, form a combinati&ii'tdge j>rtri/iW to the plamcf 
ihm' axm ; thus, two faces (such as a: 2b: 3c, or SP2 and a: 2h : ^c, or 6P2) 
whii^h cut the ortho- and clinodiagonal proportionaliy, intersect in an edge parallel to 
llie baiiial section. 

The combination of the basal end-face oP witli the prism od P {fy. 284), so fro- 



Fff, 284. 



Fig. 285. 





qnently predominates in monoclinic crystals, that it may be conveniently taken as the 
starting point for the description of the rest. This combination is an oblique rhombic 
prism. The en deface oF is set eynMnetricaUy on the edges h situated in the clino* 
dittgonal Koction, obliqnoly on the edges a in the orthodiBj^nal section. This combi- 
nation may sometimes Ihj easily mistaken for a rhomWhetlron, namely when the 
prismatic edges b are nearly equal to the comLiniitioQ-edges bt*tween oP and ocP. 
Ferrous sulphate {Fe*SO* + 7H^0), when part of the iron is replaced by another 
metal, an by copper, often taken tfie form represented in Jiff. 286, which, if the face 
4- P oc ^»e removed, and the form of the cryatid completed in the manner shown by the 
dotted liiie«, hds veir much the appearance of an acute rbomljobedron, and has in fact 
actually bcfu mistaken for one. In the rhombohedron, however, all the faces are 
eimilar, and the crystals cleave with equal facility parallel to either of them ; but 
ferrons sulphate exhibits very distinct cleavage pazullel to oP, and much less distinct 
paniUel to oc P. Moreovi^r, the face oP maJLefl with a& P to the right in front, an 
angle of 80° 37', and oo P to the right in fi^nt makes with ce P to the right behind^ an 
angle of 82° 21', whereas if the crystal were rhombohcdral, these angles would bo 

* OaTiH^i fpcitioU (nr tlic tnrmt of (he moniH'linlc iji^ti'in arc tbciiim^ a« Cho»c forllifi rbombic «f»tem 
(•tH- imir jifliffp N.*t). CIt'l•|^tkl|f thai an acrent U \AiiFfil ovor all Diimprah qr leU«r» nUitnttg to the ctiao' 




MONOCLINIC SYSTEM. 



153 



equal ; and the face + Poo is an isoeceles triangle re49ting symmetrically on oP and 
obliqoely on the two fiices ooP, whereas, in a rhombohedral crystal, the corresponding 
fiu!« oP of the hexagonal system would be an equilateral triangle resting symmetricallj 
on all three hcea. 

The clinodiagonal edges b of the prism oo P are symmetrically truncated by the 
orthodiagonal end-faces ooPoo, as in sugar {fy. 286). When this combination is 
developed at one end only of the orthodiagonal, it is not easily distinguished from the 

hemihedral combination ooP. - of the trimetric system, exhibited by sulphate of 

magnesium (/^. 281, p. 160)i supposing this latter to be developed at one extremity 

p 
only of the principal axis. The two faces — of fy. 281 may then exhibit much the 

same character as the faces oo P of the oblique rhombic prism (Ju/. 286), two faces 
oo P of Jia. 281 being likewise situated like the basal end-faces oP of the oblique 
prism, and the other two like the orthodiagonal end-faces ooPoo . The two forms differ 
nowever in this respect, that the four faces ooP of the rhombic prism are similar, 
whereas the faces oP of the monodinic ciysttil are dissimilar to the faces ooPoo . 

The orthodiagonal edges a of the prism ooP are symmetrically truncated by the 
clinodiagonal end-faces [ ooPoo ], as in ferrous sulphate {fy. 287), and in acetate of 
sodium l/ig, 291). 



Fig. 286. 



Fig. 287. 





Fig. 288. 



f'tg. 289. 





The combination-edges between oP and ooPoo (fy. 286) are of two kinds, two acute 
(the right above and lefl below) and two obtuse (the left above and right below). The 
former are truncated by the ■♦• faces, the latter by tlie — faces of the orthodiagonal 
dome + P 00. Fig. 288, shows the acute edges truncated by + Poo , a modification 
often occurring in sugar. The four combination-edges between oP and [ ooPoo ] are 
similar, and are truncated by a clinodiagonal dome [Poo ], as in ferrous sulpnate 
(fy- 289). 

The combination-edges between oP and ooP (Jig. 284) are of two kinds, four acute 
w (the two right above and the two left, below) and four obtuse v (two left above and two 
right below). The former are truncated by the + faces, the latter by the — faces of 
a pyramid + P, having the same ])a8e as the prism. Fig. 290 shows the former in 
the combination ooP. oP . +P of formate of copper; Jig. 291, the latter in the com- 
bination ooP . oP . [ ooPoo ] . — P of acetate of sodium. The + and — faces of P 
may likewise occur together, as in the form of ferrous sulphate shown in Jig. 292 ; but 
this is accidental, the occurrence of cither set of faces being quite independent of that 
of the other. 

The combination-summits between oP and ocP (Jig. 284) are of three kinds. Four of 
them, 4r, situated in the orthodiagonal principal section, are similar, and arc truncated by 
the feces of a clinodiagonal dome [P oo ], or more generally [wPoo ], as in sugar (fig. 288), 
and in ferrous sulphate (Jigs. 289, 292). Of the other four combination-summits, y, r, 
(situated in the chnodiagonal section), the two, x, which are opposite to the acute angles 
of the axes, arc acute, and truncated by the •»- faces of uu ortuodiagonal dome •»- Poo 



154 



CRYSTALLOGRAPHY. 



1^^.290. 



Fig. 291. 





or •¥ mPao , while the other two, y, opposite to the obtuse an^es of the axes, are obtuse, 
and are tnmcated by the — fiaces of an orthodiagonal dome. Fig. 293 exhibits the former 
of these modifications, Jig, 294 the latter, and Jig, 292 both together. All these are 
forms of ferrous sulphate. When the -i- and — faces of the primary form P occur 
together, the terminal edffes, C (Jig, 283), between the principal axis and the ortho- 
diagonal may be truncated by the clinodiagonal dome [Poo ], with formation of parallel 
combination-edges, as in^i^. 292. The terminal edges of P opposite the acute angles of 
the axes (the edges A, Jig. 283) are truncated by + Poo , with formation of parallel 
combination-edffes ; and those opposite to the obtuse angles of the axes (B, fia. 283) 
are replaced in like manner by —Poo . Both these modifications are seen in Jig. 292. 
The + and — £Eices of an acuter macrodiagonal dome replace these summits, with 



Fig. 292. 



Fig. 294. 



>-<d 




OP ^^ 




r 


«p 


"-"-J* 




•P ^ 




formation of combination-edges converging towards the extremities of the prindpsl 
axis, as.m acetete of copper (^. 296) and in sulphate of nickel and potassium 
(Jiffs, 296, 297). In Jig». 298, 299, wliich represent the same combination of ferrous 
sulphate, ooP . [ ooPoo] . oP +Poo . -Poo . -P. -i Poo in two diflTerent positions, 
the fiBoe -Poo is recognised by truncating the terminal edge between each pair of 



MONOCUNIC SYSTEM. 



155 



— P Uteu, with Mitllel combination-edges. In the same fignrefl, the fiicee of an 
obtaMT dome — |Pao indoded in the general fonnnhi — mPoo (^ere «i< 1) may be 
leeogniaed bj ftnunff with two eontiffaoiu — P faces, combination-edgea which direige 
towinda the enda of the piineipal azu. 

The orthodiaflonal edges of odP aie bevelled by the &cefl of a prism of different 
base [ odPh] witib longer ciinodiagonal, aa seen in fy, 296, where the bereling fiicea 
ate [ aDP2] ; on the other hand, the dinodiafonal edges of ooP are bereled by the 
&eea of a prism odPii, with longer orthodiagon^. 

The ends of the prism ooP are acuminated by the + an(l — faces of the pyramid 
P with equal base, as in gypsom (Jig. 300). As the faces + P and — P are qmte inde- 



Fig. SOO. 



Fig. 301. 





jPV7,802. 



Fig, 303. 



Fig, 304. 




Fig. Z06, 



Fig, 806. 





pendent of each other, one set may be quite subordinate or even absent, in which case 
the opposite set of faces form oblique bevelings at the ends of the prism, as in gypsum, 
ooP . -P . [ ooPoo ] (>^. 302), and augite, ooP . + P . [ ooPoo ] . ooPoo (Jig. 303). 

Faces of other pyramids likewise occur in monoclinic combinations, but generaUy of 
such as have the same base as the primary form, with a different principal axis ; those, 
in short, which are included in the formula ±fnP ; thus borax ^chibits the combina- 
tion odP.ooPoo . oP +P . +2P (Jig. 304). 

The preceding^ detaib show that monodinic combinations generally exhibit consider- 
able analogy to those of the trimetric system ; the chief mfference between the two 



156 



CRYSTALLOGRAPHY. 



4 



IB that in the former* lieraipyramids and Uemidomfla occur, whereoji in the lutt^r Uip 
pymmicla and domes are ^jjcnondly |ire^^nt with all tht^ir faces. A trimetric crystal 
properly placed, L*xhibiti» the fiame di'velopment in front u behind, and the same 
to the ri^ht Jia to tho left; but a raauoclinic eiystal placed a» deficribed at ptige 161, 
though it pjLhibitfi the same development aboTo backwards aa abore forwarda, ia 
diff<irently dovelopod to the right above and to the left above. 

The choice of a principal axis is subject to the same uncertainty m in the trimetric 
system, arising fi^jm the dretim stance that difft^w^iit cryetjils of tlie same sub&tauco 
may exhibit the greatest prismatic development in differt'Ut directions. An instance of 
this is itflRjrded by the two forms of felspar represented in J5bs. 30fi, 306, the former 
Wing most elongated in tho dire?clion of the principal axis, the latter in that of the 
clinudiagonaL 

Tho determination of moDodinic crystals is affected with a further ioui«e of uncer- 
tainty. In the case of a trimetric crysIaL, doubt nmy exist as to the choice of the prin- 
cipal oxIb^ and as to the dimensiona of the primary form* !)nt not as to the quality of the 
Bereral faces, t. *. whether they are pyramidal, prismatict or terminaL But in a monodiiue 
cT^'stal, any two similar faces may be regarded as terminal, or us forming a hemi-tlome ; 
any four similiir foces as fonnlDg either a prism^ or a dinodis^nid dome, or a bemi* 

i>ymmid ; and in fact the same &ces of u monoclinic crystal iire oft^^n regarded in diift- rent 
i gilts by different obBcrvers, according to the particular varieties which have eomo 
undtr tlieir notice. If gypsum occurred only in the form shown in fy. 302, the faoes 
there marked — P might just as well be regarded as belonging to a diuodingonal dome ; 
but the occurrence of the variety of tho same aubstance rt'preaentcd in^^. 3ul, renders 
the former view of theie fkcet pr«fi!nibl& The only rule that can be given for these de- 
terminations is to choose the axes and assign the relations of the faces in tho simplest 
possible mazmer, having regard to all the varieties of form that a substiinec presents. 



Fiff, 307. 



Fig. 308. 



%. 310. 





Monoclinic crystals present a prismatic, tabular, rhombohedral, or pj-ramidal cha- 
racter, according to the predominance of particidar fuceSL The prismatic is the pre- 
vailing charact'er, as may be seen from the instances already adduced. When the 
three contorminoua edges of an oblique rhumbic prii^m, <»P . oP, are nearly equal, the 
combination, as already observed, has v^ry much tho aspect of a rhombohcdnm, bat 
may be distinguished therefipum by the inclinations of the faces, and by the character 
of its modificatjons ( pp. 1 4 1, 152). The tabular charactex arises from the predominance 
of the t*^rniinfd faces, aa in acetate of zinc, oP . cxP . + P. +2P30 , c»P» (j^. 307). 
where the predominant faces are oP, and in ferrous sulphate^ ^. 306, where the tabular 
form arises from the predominance of + Poo , as may be seen by comparing thiii form 
with Jiff. 309, which eontains the same faces, but in difTerent proportion, 

A pyramidal eharacteir is often given to raonoeUnic crystals by the occnrrentce of one 
or more ho mi pyramids, as in gj'psum (Ji^. 300). Another example is afforded by 
ferroQs sulphate, which e^jmetimcs cr)'stallisfv«» in the form shown injfjr* 310, the same 
as fy. 286, btjt with the fuces + Foo more developed. Sulphate of nickel and potas- 
sium {fi^, 296) also assumes the pyramidal form, fy. 297, by the enlargement of the 
faces + 2 Poo and +l\ 

Bemlliedrftl Vormm, Aa the simple forms of the monoclinic system have at moat 
but four faces, hemihedral forms are not of fit«^ueiit occurrence. The most ordinaiy 
c&se is that in which the clinodiagonal dome [Poo ] is present with only half its faces 
Thus, in sugar (Jiff. 288), the two front faces of J his dome, are often present without the 
hinder ones. In ordinary tartaric acid aim, two faces of [ P«> ] (tJie ftoiit onc« in a given 
(KXiitioii of the crystal) ore pre^jent without the oUiery, whereas in anti tartaric acid 



TRICLINIC SYSTEM. 157 

(i. 348), which differs from the ordinary acid only in possessing equal but opposite optical 
rotatory power, the other two faces of the some dome are present. Two crystals ex- 
hibiting this opposite hemihedral development are related to one another like an 
object and its reflected image, or, like the two hands, or the two halves of the face ; 
thej ore similar but not snperposible. This hemihedral relation is frequent in sub- 
•tancea possessing the power of drcolar polarisation. 

BicUnlo System* 

Didinotnetrie^ JHdinohfdral^ Hemianorthic System. — In this system, two of the axes 
are at right angles to each other, while the third (which may be regarded as the 
principal axis) is obKque to the other two. The occurrence of diclinic crystals has 
not yet been demonstnted with certaintv, and as their simple forms and modes of 
combination are very similar to those of the following system, it is unnecessary to 
dwell upon them. The primary form is a symmetrical eight-sided pyramid, the basal 
section of which is a rhombus, and the other two principal sections rhomboids. 

THoUnlo System. 

Tridinometrie^ Tridinohedral^ Anorthic^ Anorthotypic^ Doubly oblique prismatic, 
Qincrkomboidal System (EXn-und eingliedriges, Tctartoedrisch-rhombiscA'trimetrisches 
System), 

Crystals of this system have three axes, all obliquely inclined to each other, and (in 
all actually observed forms) of unequal length. The axis in the direction of which 
the crystal is for the most part prismatically developed, is regarded as the principal 
axis (r), the other two as secondary axes, the longer being called the macro dia- 
gonal {b\ and the shorter the brachydiagonal (a). In representing triclinic 
crystals, the secondary axes arc supposed to lie in a horizontal plane, one or the other 
being drawn from loft to right, accordingly as the peculiarities of the crystal may be 
most conveniently exhibited. 

For the complete determination of a triclinic axial system, five magnitudes must bo 
given, viz. the lengths of two of the axes referred to the third as unity, and the three 
acute angles which they form with each other ; and for this determination, five inde- 
pendent measurements of the inclinations of planes are required. 

The primary form in this system is a pyramid whose faces cut the three axes at the 
distances a b c from the centre. Fiy, 311 exhibits such a pyramid, which may be re- 
garded as the primary form of sulphate of copper (Cu*SO* + 6H*0). a a is the brachy- 
diagonal, 6 6 the macrodiagonal, c c the principal axis; a: b : c ^ 1*027 : 1'816 : 1. 
The acute angles of the axes are a : 6 « 77° 37' ; 6 : c = 82° 21'; a: c ^ 73° 10'. 

The eight faces of this pyramid are of four kinds, only each pair of parallel faces 
being similar to each other, and each pair may occur in 
combinations quite independently of the rest. The six Fiy, 311. 

Bommits are of three kinds. The three principal sections, 
and indeed all sections parallel to any two of the axes 
are rhomboids. Of the twelve edges, only the parallel 
pairs are similar. 

Of the four front faces of the pyramid, the right above 
ii des^i^ed by F, the right below by P^, the left above 
by T, the left below by ^ ; each of the back faces is 
designated by the same symbol as the front fsLce to 
which it is parallel 

Other pyramids having the same base as tho primary.form are denoted by the 
general symbol mP, and those having different bases by mPn and mPn, just as in the 
trimetric system. Each of these pyramids has faces of four kinds, each pair of parallel 
Ucee being independent of the rest, and capable of occurring without them. The 
several faces of any individual pyramid are distinguished as to their position in the 
manner described for the primary form. 

There are also triclinic prisms, ooP, of the same base as the primary form ; also 
prisms with different bases, ooP» and cotn. Of the four faces of those prisms, only 
the parallel pairs are similar, and either pair ma^ occur without the other. In the 
prism ooP ^for a position once determined), the right front face and the one behind 
parallel to it are denoted by ooP/, the other two by oo^T, and similarly for the other 
pnsms. 

Domes parallel to either of tho secondary axes are denoted by tho general symbols 
siJ^Qo MnamPco ; in these also onl^ tho opposite faces are similar to each other ; a 
psir of such &oes oocnrring (for a given position of the crystal) in front above and at 




us 



CRYSTALLOG R APHY. 



Fi>. 312. 



the back below nn* denoted bv the eymlxjl m'P'oa , or wi'P'oo ; in ttoni below^ and 
bobind aboTe, bj w^P^oo , or wP^co ; to the right above and left below by mj^xt , 
or mP'co ; (o llu* left aboTO and right bolow by m'l^jjo , or f)i'1^^<t> . 

Lastly, tlii*re are tJie bae^al end-face» aP, the maerodittgomd end-faceg col* go ^ and 
the brae hy diagonal end-faces ocPoo ^ each pair of which eats otio of the axos and is 
parallel to the other two, as in the trimetric Byatern. 

All triclinic crystals are oomblnatioas made up of paira of opposiJ^e faces of the 

eimple formi*. Each pair of parallel faces may 
be dcaigniited in various wmya, citJier us end- 
faeos, or afl parallel faces of a prism, or of a 
pyramid* If^ as frequently happens, three pairfl 
of faces are predominant, as in Ji^, 312, the 
npper and under faces may be regnjrded as oP, 
the others an od/P and wP/, or aa od^os and 
ocpao . 

Fiffs. 313, 314, 315 represent three forms of 
aulphate of copper, referred to the primary 
farm represented in^ 31L 
Ftff. 313 consists of the primiiiy form modified by the end-faces ckPos and ooP«c ^ 
and \h& hemiprisms oo T and ccP ', If, however, only the F faces of the primary 
pyramid are present (the ton aiid bottom faces in the figure), and these faces, 
together with the faces parallel to tUe principal axis, are extejided till they meet, 
the result is f^. 314, the most common form of solphate of copper. Other fa<»e6 like* 
wiae oceuTr though Io&b developed. In determining the rclatiooj of theae* and of tri- 




Fig. 313, 



Fig. 314. 



Fig. 315. 




clinic combinations in general, the same mle holds good, eis in the other systems, tjz. 
that faces whose combination- edges nw* paraUvl to a principal section, cut the two 
axea contained in that section at proportional distances from the centre. In Jig, 315 
the heittidomes 2^^oo . f'oo , *P<d , 2^X^00 , and the basic end-fit ce oP, which are all 
parallel to the bracIiTdiiigonal, form with one another and with ocPco combinaLion-edgca 
parallel to the basal principal section ; oP forms with P* an edge parallel to that be- 
tween P' and ooP/. In Jkf, 3H, the edges bt-tween P* and coPoo are parallel to the 
macrodiagonal principal section ; the faces which (in^. 315) truncate Uiese edgea cut 
the principal axis and mncrodia^'onal in the same proportion aa F, that is to say, if 
they are also parallel to the bmchydiagonEil, they Ix^oug to the dome ^00 . The facfl 
Jl^'<x> is recognised by this charneter. 2^F'oq tmneates the (acute) edges betwe«en P' 
and OD^T, The edges between P' and cnPao are ptirnllel to the brachydiagonal prin- 
cipal section; in fy. 315 they are mrtly truncated by the faces of a pyramid, 2F% 
which cut-s the principal nxls and brachy diagonal in the same proportion as the 
primary form ; instead of these faces, or together with them, are sometimes found the 
faces 3P3. 

The edges between the end-faces parallel to the principal axis and the acyaeent 
prianiatie faces are dissimilar, and either may be modified without the other. Thus, in 

^ " ~* are often truncated by 

; sijnilarly, two face9 

between ooPao and 




I 
I 
I 



I 



CRYSTALLOGRAPHY. 159 

Acgreffttttoos of Crystals. 

Crystals of the same sobstanoe are freqaently united in gronpe, sometimes regularl v, 
sometimes izregalarly. Aluni often forms gronps of crystals regularly combined in 
the manner shown in pgi, 316, 817, the octahedrons b^ng united with their edges 
panllel to each other. 

Aggregations of cubes end to end, so ss to form elongated prisms, are also of fre- 
<{aent occurrence^ as in chloride of potassium, which, under peculiar circumstances, 
has been seen to form thin silky threads, like tufts of cotton grass, made up of micro- 
soupic cubes (Warington, Chem. Soc Qu. J. yiii. 31). Chloride of sooium some- 
'* ^ crystallises in sudi a manner that four such prismatic aggregates of cubes unite 

Fig. 8l6. Fig. 317. 





together by their extremities, fbnning a hollow frame, and on this frame smaller ones 
gunilariy constituted are successiTcly built up, till a four^sided pyramid is produced, 
eompoeed wholly of little cubes ; sometimes again it assumes the uivorted position, like 
afimneL 

Oronpe of crystals (excepting when formed of cubes or prisms laid end to end) may 
always be distinguished from single crystals by presenting re-entering angles (^«. 316, 
317). Sometimes, however, the re-entering angles are so shallow as not to be percepti- 
ble without the use of highly magnifying powers; the crystal then appears striated. 
Suppoee, for example, the number of octahedrons united as in ^. 316, to be so much 
increased, and the distance between the horizontal parallel edges proportionately di- 
minished, that the individual crystals can no longer be distinguished. The mass would 
then present the appearance of an octahedron having its horizontal edges replaced by 
prioDatic faces, and those faces horizontally striated. Such striations, which are fre- 
quently observed on the faces of natural crystals, afford good indications of the internal 
■Inietiire of the crystal, and of the manner in which it has been formed by the juxta* 
poaitioii of successive layers. 

Twin Crystals. 

When two crystals are regularly aggregated, but not according to the parallel mode 
of arrangement just described, they are called twins or macles; twins by contact, 
if the two individuals extend only to the plane of junction ; twins by intersection, if 
each of them is continued beyond this plane and through the substance of the other. 
The plane of junction is always parallel to a face of the crystal either actual or possible, 
and one of the crystab is turned from its original position through an angle of 180^, 
round an axis perpendicular to the plane of junction. 

The two crystals thus united are seldom fully developed, but for the most part 
only firagments of an ideal crystal ; in many cases, each of them is the half of a com- 
pletely developed crystal, and then the combination is called ahemitrope; such a^- 
pegates may be supposed to be produced by cutting a perfectly developed crystal in 
halves paraUel to one of its feces, and turning one of the halves through an angle of 180^. 

In the regular system, twin crystals of this kind arc found tearing this relation 
to the regular octahedron, as shown in the annexed figures, where, if wo suppose the 
octahedron ijig, 318) to be cut in two by the horizon^ plane indicated by the dotted 
lines, and the upper fragment turned half round, the twin crystal {fig. 319) will be 
produced ; examples of this arrangement are found in nitrate of lead, alum, magnetic 
iron ore, spinel, &c Hemitropes also occur formed in like manner from the cube, 
regular dodecahedron, and tetrakis-hexahedron ; an example of the last is found in 
native copper. 

In most eases, twin-crystals thus formed may be distinguished from simple crj-stabi 



160 



CRYSTALLOGRAPnY, 



bj the oecTirrenco of rc-eiiteriiif* niigU^; uudpr poealiai" circnm stances^ however, twins 
may be formed without riieiitoring auglcs, as in some cusrs when each indivftiuai is 
BtiiaMer than the half of the ideally perfect crjgtAl, or when the plane of junction ist nt 
right angles to the fuee^j tkrongh which it passeSf aa ia some cases of twin-foniuition 
frgm the regular dodecahedron. (Sec Kojfp'a Krystallograjthie, p. 87.) 



Fig, 31S, 



Fig. 319. 





InterBQctinj^ twins ore ofl^^n formed from tho cub« (a» m ilizor-apor^ galeDA* stl- 
ammoniac, cMonde of potasaium, &c.), the phme of jtuiction (passing through the fix 
reentering angles Bituatod in ooo plane) being situ at ed Hte the fuce of an octahe- 
dron {jig. 320), In these twin«, and in all tJio«e which are derived from the holoho- 
dral forma of the regular Bystcm, the individual crystals are intergrown in such a 
manner that their axi^ sjtfCenui are not pioallel to one another \ indeod, two holohedjitl 



Fig. 320. 



Fig. 321. 





formSj so long as their axes pomain parallel, can only unite so as to form a^rgrrogatea 
like those represented in Jigs. 316, 317 ; as soon as they are brought togt'ther in such a 
manner as to haTC a common eeiitfe and paralli*! axes, they coincide al together. hu% 
hemihodral ciysttda ofte>n form intersecting twins, with parallel system of axes^ like the 
two tetrahedrons mjig» 321, becauBC, though tho oica are parallelj the faces may lie 
in opposite direetiona. 



Fig, 322. 



Fig. 323. 



^ 


^ 


y 


S: 


>>. 


y^ I / ^ \^^^^ 


t^^^ / 




"r 












at 


4 


V 

f- 


r^ 




L'' 








.^ 


^'' 








c''>' 




















L^ 


— 


—f'~ 


'^^ 




In the dime trie or quadratic system, twin^cryatalsoccurboth with parallel and 
non-pjrallel systema of axes. The former occur buf rarely^ and, as already explaine<l, 
only in heniihcdrallonna. In t«i'»ecting twins, like/*/. 321, are somctinies formed from 

P 

quadratic aphcroYds, h^ -^ , as in copper pyrites. The same min<fnd also furms hemi- 



CRYSTALLOGRAPHY. 



161 



P P 

tropic crystalii, like fg. 319, derired from the quadratic pyramid + -^ and — - 

equally dereloped, which haa the same nhape as tho regular octahedron. 

But thA most frequent twin-formation in the quadratic system is that formed by 
two crystala united by a face parallel \o Poo , one of them being turned half round. 
¥ig. 3*22 is a form of tin-stone, ooP . P . ooPoo . Poo . If this ciystal be divided iu 
the middle by a plane parallel to Poo , and the lower half turned through an angle of 
180^, the form represented in >^. 323 will be produced. 



Vlg, 324. 



Fig, 326. 



-+« 



/s^c:^. 



In the hexaeonal system, intersecting twins are formed by two rhombohedrons 
penetrating each other like the 



Fig, 326. 



Fig. 327. 



cubes in jig, 320, and having the 
face oP in common ; this form ia 
exhibited by chabasite. Contact 
twina are exhibited by several 
fonna of calcspar; thus, if we 
suppose the crystal represented 
in fitt. 324 to be cut through the 
mid^Ile by a horixontal plane, and 
the lower half turned half round, 
a hemitropic form will result, like 
that in fig, 325, which haa tho 
peculiarity of not exhibiting any 
re-ent<>ring angles. The scale-- 
nohedron \fig, 326), cut through 
the middle and turned half round, 
yields the form shown in jig, 327, 
which is often very regularly de- 
veloped in calcspar. 

In thetrimetricorrhombic 
system, twin cxystals with paral- 
lel axial systems are of very rare 
occurrence. In those with non- 
parallel axes, the cnrstals are 
generally united by a uce of the 
prism ooP, or of the macrodiagonal dome Poo , or of the brachydiagonal dome l^oo . 
Fig. 328 shows tho combination ooP . oof oo . Poo occurring in arragonitc. If we 
suppose this form cut in halves by a plane parallel to the left front face ooP, and the 
K*ft hand fragment turned through 180^, the hemitrope {fig, 329), which often occurs 
in arragonite, will be produced. The re-entering angle between the two front faces 
otf 00 ia, however, frequently overgrown by the enlargement of the adjacent faces ooP. 

If we nippose the combination P . Jr oo . oo 1^2, occurring in sulphate of potas- 
sium {fig. 330 without the fitce 3i^ao ), to be halved parallel to the face f oo in fVt>nt 
below, and the lower half turned round 180^, the hemitrope, jig, 331, will result, 
which is a common form of sulphate of potasoium. 

In the monoclinic system, as hemihednd forms are very rare, nearly all the twin 
crystals which occur are such as have their axial systems not paralleL The contact 
face is almost always parallel to the orthodiagonal and one of the obliquely in- 
clined axes, liiat is to say, either to tho orthcKliagonal end-faces oo Poo , or to the 
basie end-fiiice oP. The twins are for the most part contact twins. 

VouIL M 





162 



CRYSTALLOGRAPHY. 



Fig. 828. 



Fig, 329. 




Tho twins whose contact-face is parallel to ooPoo are often composed of indiridiials 
which appear like the halves of vory ro^lnr crystals. If we imagine the forms repre- 
sented by fig, 332 (gypsam^ fig* 334 (ferrieyanide of potassium), and/y. 336 (avgite). 



CRYSTALLOGRAPHY. 



168 



to be cnt in halves by planes passing through the orthodiagonal and principal axis, 
and ono half of the cinrstal turned through an angle of 180^, the first will produce 
Jig, 333, the second, fig, 335, and the third, fig, 337, twin formations of frequent 
oocoiTence in the substances above mentioned. 

In many instances, the two half«-cr}'8tal8 composing a hemitrope formed in this 
manner, are not such as can be derivr^d from the name, but belong to different 
crystals. An example of this mode of formation is presented by fohtpar (orthoclasc). 



Fig, 338. 



Fig, 339. 



Fig, 340. 



Fig, 341. 




If the combination, ooP. [ooPoo] .oP. + 2Pao {fig. 338), exhibited by this mineral 
be supposed to reTolre through 18(P round a line a 6, perpendicular to the ortho- 
diagonal section, it will be brought into Xhb position shown \nfig. 339. Thpse two 
cxystals (which we will denoto by ^ and q) are, therefore, in the relative positions re- 

2uired for the formation of a twin crystal, according to the manner under consideration, 
(ut the mode in which they actually unite is this : Supposing each crystal to l>o cut in 
halves through the clinodiagonal section (as indicated by the dotted lines), the front 
half of /> unites with the back half of y, producing/^. 340, and the back half of /? with 
the front half of y, producing y^. 341. The two twin crj'stala thus produced are re- 
lated to one another in form just like an object and its image reflected in a mirror. 

In all the preceding twin formations of the monoclinic system, the principal axes of 
the individual crystal remain parallel, though the secondary axes do not. When, 
however, the contact-faces are parallel to the basal end-fucc oP, the principal axes of 
the two halves do not remain parallel ; such a mode of union is exhibited by acetate 
of copper {Jig. 342). If this oystal bo cut in halves parallel to oP, and the lower 



Fig.Z\2, 



Fig. 343. 





half turned round throneh 180^, the result Is the hemitropic crystal shown in fig. 343. 
If the development of each crvstallinp fragment be continued beyond the contact plane, 
an intersection twin will result ; such a mode of formation is exhibited by sphene. 

In the triclinic system, twin crystals are of somewhat rare occurrence; an example 
is, however, afforded by triclinic felspar (albite). The contact-fieice is in many cases 
parallel to oePoo (corresponding to ooPoo in monoclinic felspar)^ and then twins are 
podaced Teaeinblmgfigs. 340, 341. In other cases, it is parallel to oof oo (correspond- 
ug to [ ooPoo ] in monoclinic felspar), and these last-mentioned twins exhibit the tri- 
clinic character very clearly. If a crystal of monoclinic felspar be cut in halves 
through the clinodiap>nal principal section, and one half turned round through 180^, 
the crystal still exhibits the same form as before ; for the portions of the oP faces 
thus brought together fidl into one plane, as also do the contiguous portions of ^e 
laces 2Pao . But if a crystal of triclinic felspar {fig. 344), in which oP is obh'que to 
otP» , be thus divided through the brachydiagonal section (as indicated by the dotted 
liiMi), And one half tamed round through 180^, a hemitropic cnrstal {fig. 346) will be 
fonned, in which one end (the upper end in the figure), oP, of the one half forms with 
QP of thtf oihM \aH a ro-entering angle of 173^ 48'; and .Foo Ibnns with ,Fao a re- 

M2 



164 



CRYSTALLOGRAPHY. 



tig, 844. 



Fig. 346. 





entering angle of 175^ 12', whilst at the other end, the correBponding faces are inclined 
to one another in projecting angles of the same magnitude. 

Twins also occur in the tridinic system, in which the indiriduals are united by a 
&ce parallel to oP. 

ZmperDBOt and IMstorted Crystals. 

Crystals are often imperfectly developed, or not bounded all round by crystalline 
faces, in consequence of being attached on the side to a matrix or to the surface of a 
ressel ; and in very many cases they are distorted, that is to say, some of their 
similar fiices are more developed than others, and may thus acquire even a different 
form. In all cases, however, their inclination to each other and to the axes remains 
unaltered. Every distorted crystal may be referred to a regular form, by supposing 
certain faces of the latter to approach nearer to the centre thui the rest, or slices to bo 
cut from the crystal parallel to certain &ces. 

Octahedral crvstals of Uie regular system, such as alum, often exhibit only one 
complete octahedral face, the crystal having grown to the surface of the vessel by the 



Fig. 346. 




Fig, 347. 




Fig, 348. 



Fig, 349. 





face fl 6 c d ef (fig. 346) so that the portion below that pkno has not been developed ; 
n:.^TS ''''ili?l"S'^' of the crystal, shown in fia. 347, is developed, as if The (^I 
hedion (fig. 846) bad been shcod parallel to the right front face O, iindicated by the 



CRYSTALLOGRAPHY. 



165 



dotted lines. Nitrate of lead, which crystallises in the niiddlu form betwo<^n the cube 
and octahedron {fi^. 176)| often exhibits only portions of this form, Kkc that bounded 
hj the thick linee in^. 348, the crystal having grown to the surface of the yessel by 
the plane ah c d ^/parallel to 0. 

Cubic CT^-stals are often reduced to square plates by being less developed in the 
direction of one axis than of the other two ; sometimes again they are more or \ees 
elongated in the direction of one axis, as if a number of cubes had grown together by 
their faces, and thus acquire the appearance of elongated square prisms (p. 169). 

Octahedral crystals abo are sometimes elongated in the direction of a line joining the 
middle points of two of their opposite &ces, as shown \nfig. 349, where the thin Tines 
represent the ideal octahedron and the thick lines the distorted form. This distortion, 
which is seen in chrome-alum and nitnite of lead, gives the crystal the appearance of 
a rhombic prism bevelled at its extremitii'S by the triangular faces resting perpendicn- 
Itfly on the acute edges of the prism, like Jig, 267, p. 147. 

Similar imperfections and distortions occur in crystals belonging to the other systems. 
Aqaadratic pyramid {Jtg, 217» p. 133) may be shortened or elongated in the f 



Fig. 350. 



Fig, 361. 





minner as the regular octahedron, exhibitinff forms like figa, 347 and 340. The com- 
bination of P and odPoo equally developed {fig. 360), which is the normal form of 
potaMio-capric chloride, often uppears distorted in the manner shown in fig. 361, by 
elongation in the direction of a terminal edge of the pyramid, tliereby acquiring the 
appearance of a hexagonal prism with trihedral summits. 

Qoartx, the normal f(»rm of which is a hexa^o nal prism with p}Tamidal summits 
P. «P (fig. 154, p. 117), seldom or never exhibits this form in perfect regularity, some 
of the facetf being more developed than others, as shown in fi^, 362. Khombohedrons 
also are often reduced to plates by shortening in one direction between two parallel 
£ires, or elongated to prisms by abnormal development in the direction of one of the 
edges. 

Fig, 362. Fig, 363. 





Fig, 364. 




In the t rimetric or rhombic system, the most common distortion arises from the 
uieqiisl development of the four faces of a prism ooP, two of them being larger and 
nearer to the centre than the rest, so that the transverse section, and the end-fiice in 
the combination ooP . oP, is altered from a rhombus to a rhomlioid. The true 
chamet«r of the crystal, may, however, be recognised in soch cases by the cleavage 



166 



CRYSTALLOGBAPHY. 



and by the modi fioat ions. The crj*8tiil, if dr^aTtible parallel to the prismatic Ikecs, 
fcpltta as easily ia the tliret-'tion of the smtiUor as of the lurii^er of thes« faces. If an 
tmlgc of tho distorted prism is truncated, the trim cation -fat-'c la tii^iiaUj inclined to tho 
two adJa<!^ont. face.% ooP^ and if its cmls are beveled by domes, the faces of the doiaen 
are likewiHe equally inclined to the two [irismatic faces. 

Monoclinio crystals exhibit similar distorfioni*; iudeed the laces of an oblique 
rhombic prism are almost always unoqually distant from the epntre» so that the tranfl' 
Tt»r9i3 B^ction becomes a rhomboid iiiBteiad of a rhombus. Cryst-ala of ferrous sul- 
phato of the norma! fonn shown in Jt^. 353 are often distorted in such a manner that 
two paralltil fac€« ocP and the basic end-fiices oP are very much dc^veloped in one 
direction, producing the form ahown in fy, 334 ; if the crystal is develo{>ed on one aide 
only and attached on the other, the di^culty of Tecognising it is of course coD^iderably 
increased. 

Curvature of Cr^stah.—TliQ surfaceti of cryatala are eometimes carved, in ooiuie- 
Quenco of curvature in the laminae of which the CEjBtal iu made up. Crystals of 
diamond often hare their facea curved to such an e>xt«nt, aa t^o make them appear 
almost like spheres. More fhsjucntly, a convex surface is opposite and parallel to a 
eoncave surface. This kind of distortion ia seen in spathic iron, the cryatala of which are 
aomedmes fiaddle- shaped, in conseqnonce of several curvature occurring in the same 



fiuiew 



Fifj. 355. 




Fig. 35fl. 




I 



Another kind of curvattire ia Bf«n in prismatic and agpTPgated crystals, and h efp^ 
cially freqwent in such as are implanted or imbL^lded, Fitj, 356 exhil»it'? thin kind of 
distortion as seen in quarbs, Six-sidid jiri^^ma of cnltHte and priHraatic cryatala of 
gypsum arc sometimes curved in a aowiewhat similar manner. 

In many species, the ery.stida appear as if Ihey had been broken transversely into 
peveral pieces^ a slight displacement of which hnn pven a cnned form to tlie pnani. 
Ttii.H ift common in tounnalin and her}!. The beryls of Monroe County^ Connecticut, 
oftvti pre«ient ititrmaptod curvatures, as shown in Jtg. 35fi. (Dana.) 

Most of tho du9t4>rtion?t above deKcrilit'd oeca«ion no change in the inclinations of the 
Hc96 of cr}stal8. But those imperfeetiona which produce curvinl or striated faces 
aeoeMarily lead to vtiriationa in tiie aii|y;li^. The HurfiUfS of lai>J!t^ er}'stals ot>i>n have 
a eewnposit© character, appearing^ when examined by a magnifyinj^ ^huss, a.« if tht-rts 
had been a tendency to tho formation of timaller crystals while the cryHtal wm 
growing. Octahe^lnios of fltior-sf«ir sometimes have their faces made up of little en be:*, 
^ach a cause proilnce*i more or Ichh irregularity in the planes and their inclinutiens. 
Variations of form and anj^ar ma|i^tntude also ariae from the presence of foreign 
parti ele«t entan^^lwl in the crista 11 iMiig mineral. Even the pri^M^nee of foreign in- 
gre^lieuts in jsolution when tho crystalliyation ifl going on, Hi'ems often to aifect the 
angles, and such ingredients may be inetmled in the crystal T.rithout beiiig at all 
apparent, except on aniilynisi. According to Baudrimont*H meaiturenients of c^cspar^ 
the rhombs of this minertd seldom lukvu the three angles at their Banimits exactly 
eqmd. 

The imperfoctionfl mud distortions of crystals often present great obstaclos to tho 
determiuatiotis of c-rvi^talline forms, and even, as alrea<ly observed, of tho system to 
which a cnp-^atal bd':'n^hi. In most CJLseftt angular mcjiMurement may be safely relied 
on; but e%'en this method, in coni*equonco of the di.sturbing causes just noticed^ may 
sometimes lead to erroneous resultH. In all <»hs*'S, however, excepting in some of the 
grosser distortiouit, tho eharactrr of the modiHcatiors atftjnis an unerring guide to the 
system to which a crystal hehmgH, the genervil law wldch j^overns them Iteing, that 
like parts of a cry Htal are similarly, onlik** parts dtBHJmibrly nnxiiliiHl This principle, 
already developed at .'*onjt* length in the (b'i!it'ri[>tionH of the several system!*, may Im* 
further ehit'id;itrd and racilitated in application by the following tabic t^iken imm 
DanaU Mincralofji/, L 123. 



=1 
I 



CRYSTALLOGRAPHY. 



167 



Table of Modifications of Crystals, 

I. All edges modified alike. 7 «# „ . o a 

«. Angle* tnincated or replaced by 3 or 6 similar planes, i Mohometric Sjstem. 

f Number of similar planes at extremities of crystal. 3 or some mul- ) Hbxaoonal 
UpleofS. ^ j System. 



1. All edges «o# 
BNMlMed alike. 

of the angles trun- 
cated or replaced 
bv three or six 
•untlar planet. 



front not similar to 1 **npo«»»We. J 

the corresponding ] 
inferior in rroiit or j 
tupcrior beliind. \\ 



Noraberoftlmi- 
lar planes at ex- 
tremities of cryftai 
neither 8 nor a' 
multiple of 3. 



, Two a4iaeent or two ap» 1 
\proximaU simple planes 
^possible. ] 



Triclinic 
System. 

MONOCUNIO 

System. 



N. B. The right rhomboidaj prism on its rhomboidal base 
may be distinguished from the other right prism by the dia» 
similar modifications of its lateral and basal edges and angles. 



The tuperior ba- 
sal modifications in 
front similar to the 
corresponding M- 
ferior in front or 
superior behind. 



.. Similar planes at each 
base either four or eight in 
number. 

2. All lateral f edges (if 
modified) similarly trun- 
cated or bevelvd. 

1. Similar planes at each' 
base either two or four in 
number. 

2. All iateralf edges (if 
modified) not similarly 
.truncated or bereled. 



DiMBTUO 

System. 



Trimktrio 
System. 



i 



Important aids in tho determination of the sjstem to which a crystul belongs are 
also i^orded : 

a. By cleavage, which ia similar parallel to like faces, dissimilar parallel to unlike 
faces. 

b. By the characters of surfaces. Similar planes are alike in lustre, hardness, colour, 
titriation, &c. If, for example, a cubic crystal has similar striae on all its six sides, 
it is nionometric, but if the surfaces of one pair of its opposite sides differ fiom the 
rest, it belongs to some other system. Similar cleavage-faces also exhibit similar 
lustre, &c 

c. By the optical relations of tho crystal. Monometric crystals refract light singly, 
but crystals of the dimetric and hexagojial systems have one axis of double refraction, 
and those belonging to the other systems have two axes of double refraction (p. 122). 
These characters are often of great use in determining the system to which a crystal 
belongs. 

d. The thermic relations of crystals likewise differ accortling to the system to which 
they belong, as explained at page 122; so likewise do their relative elasticities in 
different durectious ; but tho methods of observation on these points are too difficult of 
execution to be of much practical utility in the determination of crystals. (See Hbat.) 

COeawaffe of Crystals. 

Most crystals exhibit less coherence in some directions than in others, and conse- 
quently may be cloven or split in certain directions with more or less facility. Some 
OTivtai^ as mica, may be split into laminae by the fingers ; in others, a slight blow 
with a hammer is sufficient ; others require the application of a sharp cutting instru- 
ment, and often considerable skill in its use. When other means fail, cleavage may 
sometimes be effected by heating the mineral and plunging it into cold water ; this 
method sometimes succee<ls with quartz. Many crystals cannot l)e cloven by any 
means : in these cases, however, the direction of cleavage is sometimes indicated by 
lines on the surface, or by cracks in the mass of the crystal. It is often important to 
obiierve these lines or cracks, even when deavago is possible, in order to determine its 
direction before applying the knife. 

The general laws with respect to cleavage are as follows: 

1. Cleavage in crystals of the same specit^s yields tho same form and angles. 

2. Cleavage takes place parallel either to ono or more of tho faces of a fundamental 
form, or to its diagonals, or to some of the secondary planes. 

* The rbombohedron Is the only solid included in this division, any of whose angles admit of a trun- 
caikm or repUeemcnt tqr three or six planes. 

t T1m» tctntoal edges of the octahedrons are here termed lateral, in order that the statemenla may be 
fsMnllj applicable to both prisms and octahedrons. 



168 



CRYSTALLOGUAPIIY. 



a. Clearngc Is olitiiined with eqwa] ease or difficulty pamllel to simiiar faces, and 
vith unetiudl eaiip of difficulr^' pamlel to dis«imilar larcft. 

4. Cloara^' punillel Ui similar fiicea afRiifdii pLmes of almilar lustre and appeanuice; 
in the coutrar}' ciL^i\ of flisiiiiniilar lustre and appCAranw. 

Thm?* cleavugo is olttalntHl with e^ual eust* or diiBcuJty parullol to all the tax^s of a 
cuW, pepjiilflr octaliedroo, rhombic dGKlecahc<Lrtui, or rhoinbohedron, which art* b«>iinded 
bjf similar plauefl^ The right square prism, right rhombic prism, and oblique rhombic 
prism ( ooP . oP of the dimctric, trimetric, and monoolinic systems respectively) deava 
with equal ease or difficulty parallel to their lafceml planes, since theso also are similar. 
X>equentlv, however, these prisms cleave only piiMJIel to their bases, and sometimes 
not even m this direct ion. In some casest also, the elearage is diagonal, in the square 
prism alike in lK)th Terticnl planes, but unlike in the rhombic prbrart. The right ree^ 
taiignlar prism ( odF*oo » ocPao , oP, of the trimetrio Jtyslem), tbe right rbomtHavdal prism 
( ooPoo . [ ocPoo ]. oP of the monocliDic syptem) and the oblique rkomboVdiil prism 
( ccP* . OD^'P. oP, or Qcl* . 06? Qo . oP, of the triclinic system), have the cJeavage niit^ij^udl 
juLmllel to their faces, if attjiinable at all in these directions; moreorer, clcavuges 
ill tbege two directions and ptirnllel to the base yield faces of uulike lu»tre auil 
general awpeet. This is exemplified in gv'p^um, which in one direction cleaves with 
grt^ftt facility into thin Isimiiiie of perfect transparency »nd highly polished sTirfiU^f ; 
whilst in a second direction, thelamime first heuaand then htvak, exhibiting a surfut^o 
which is not smooth or i^Kjesesised of much Instre; and in a third direction, the lamime 
lire brittle, break iuimediately on at tempting to l>cnd them, and exhibit a surface 
smoother than the second^ bnt not polished. lu thick masses, the second and third 
deavages are BJ?jircely attainable. Two of these d'eavagt^ incline uit an oblique angle, 
but one is at right angles to the third, shoeing that the crjstul in monodinic. 

Meaauresieiit of Crystals. 

A crystal Is determined when wt? know the relative lengths of the axes fur each 
of the primarj' forms which compose itt iit^^l (heir inelinatioUt in ease they are not 
at right nugles to each other. Thejie roagnitndes cannot however be raeasnred dinn-tly ; 
the only element of the form admitting of dircet mea?inremeiit li* the ineliuation of 
the faoes one to aDother; and as these inclinations arc connected with the ratios and 
inclinations of the axes by fixed geometrical relations, the latb-r may l>e determined 
by cakulation, when a suJBicient numlwr of the dihedral anglfs of the crystal have 
been measured. The uuBiWr of angular ineuBurements aliftolutely required for each 
form is of course equal to the uim]lH*r of unknown quuntitic^ to be determineil; tlms 
for a aquare pymudd a: a: o (p. 133), the only magnitude to bo determined is the 

rah'o - ; and for this, one nngulnr measiirement will suffice, vi«. the angle either in tke 

c 
torminal or in the lateral edges. For a rhombic pyramid a'b:c, two quantities have 
to be determined, viz. the kngtlis of two of the axes referred to the third as nnrty, 
and fitr thif*, two rndeftendi nt measurements are re^^juired. For a mouoclinic pyramid, 
in wliieh, in addition to the two ratios just mentioned, the inclination of the prii.- 
ci[>al axis to the cHnotli agonal baa to be determinetl, three independent angulxir 
ineaiifureraenta are required. In all cases, however, it is advisable to take as many 
angrdar mcflsurements as possible, in order to cheek the values Erst determined, 

For the formuhf whieh express the relations between the inclinations of l^icea and 
the ratios and inclinations of the axes iji the several systems^ we must refer to mora 
detiiiled works*, and coniine ourselves here to the description of tJbe inslnuiieiita oaed 
iVif nu'ttsuring the angles of crystals. These iustrnments are ealled Gotjioicxtbbs, 
jiud sre of two kindsj tbe Ajtplkatum-' ar liand-^oiii&mttrr, and the lleficcting 
Gatihmtttr^ 

The hand-goniometer is a divided semicircle a hd (Jig, 357), to which are 
adapted two metal ndea, one k m being fixKi, the other ff h movable round a pin c 
nt the centre of the seniioircle. Both these rules have slit*j, so that they may be 
moved bnekwordit and forwanb^ making the sides of the angle k n h longer or shorter 
MS may Ik reqiured. A straight line tlniwn through tlie point c and the middle of the 
nde km pasjios thmugh the ^xMnts 0^ and 180^ of the divided semjcirele. The 
other ruK ^ ^. i* Tiarrt^wer in the part which moves mund thesemircitx'Ie (and likewise 
bevelled ). ho that the edge y i proiluccd would pass through the e<'ntre c. The angle 
which I be edge y / marks on the gradmited arc, is therefore eciual to the angl« n 
contained between the e«lges I- n, n A. 

The crystal to be measured is placed between the nilea k ft, n h in meh a manner 

• D rt II «♦ Sy^pvn nf MineTxIo^y, tot. i, Sto, Nrw York, TRAg. MHl #! r, Tre»ti§e on CrTttul]ofr.t)*1t> , 
tol. I. S*n. ('AinhfltJgf, IKIS. tironkr' *nt\ MU |rr, new c'UUut) of I'liithp*** MiuffMilofi^ \nMu 



I 



I 



CRYSTALLOGRAPny. 



169 



tiiat the edges of these rules may both bo at right anples to the line of intersection of 
the two faetm who^e inclination is to be measured. The edge it w Is applied close to 
aoe face of the ciystal, and the other rule ^A is moved round c, till the edge n h 
eoiucidefl exactly with the other face. The inclination is then indicated by the 
jmmber of degrees in the axed e g. 




Fig. 358. 



If one of the faces of the ciystal presents irregularities arising from small crvstjils 
being implanted on it, the edge k n must be laid closely on the smooth face, and the 
other edge n A, brought as close as possible to the other face and parallel to it. 

In measuring crysUls implanted on a surface, the parts kn^hn oi the rules must be 
Borod along the slits into the required positions. In such cases, the part a 6 of tlio 
graduated arc is often in the way. To obviate this inconvenience, the semicircle is in 
some instruments cut through at h and the two parts joined by a hinge: there is then 
also a strip of metal /• movable about c, which, when placed in the position shown in 
the figure, serves to keep the two halves of the semicircle in the same plane, but when 
mored towards f, allows tlie half a 6 to be turned round to the back of h d. 

This instrument is veiy convenient, and indeed indispensable, for measuring the 
an^es of large ci^'stals ; on the other hand, it is evidently inapplicable to small crystals 
or to such as are very soft or friable ; and as small crj-stals are of much more frequent 
oecnirence than larger ones, and generally exhibit the best defined forms and flattest 
iorfaces, the use of the liand-goniometer is necessarily somewhat limited. For these 
reasons, the reflecting goniometer of Wollaaton, which also gives greater accuracy of 
meaKurement, is much more frequently used. 

The reflecting goniometer depends upon the following principle. Ixit bao 
{Jig. 356) be a section of a crystal, the angle c of which is to be measured. The 
ciystal is supposed to bo fixed so that its edge 
is exactly in the prolongation of the axis of a 
divided circle mn p. Let a mark y (a black 
line drawn on paper for example), be so fixed 
that the eye of the observer placed at E may 
see this mark y directly, in the same direction 
as the image of an object x above the crystal, 
reflected from the bright surface h e. Now sup- 
pose the crystal to \i turned round the edge 
c till the face c a comes into the position c a\ 
in the prolongation of be; the eye placed at 
£ will still see the image of x in the same di- 
rection E y, by reflection from c a\ But it is 
evident that the angle ac a (measured by the 
arc «fc ») til rough which the ci^'stal has bwn 
tamed, is the supplement of b c a, the angle to 
be measured : hence the following rule : The 

angle a, contained Ixitween two faces of a crystal, is the supplement of the angle 
through which the cr}'stal must l>o turned, in order that these two faces may re- 
flect the image of a given object in the same direction : or if this latter angle is == a, 
the angle between the two faces of the crj-stal will Ihj 180° — o. 

The instrument by which this principle is applied to the measurement of crvntaln is 
represented in fig. 369. It consists of a vertical circle E E, divided on the eipe, and 
toning upon a horizontal axis pasniiig through the socket C, which is fixed upon the 
pillar 13, 8up|)ortcd on a heavy foot A. This axis likewise carries a smooth-edged disc 



**;^ 




y 



170 



CRYSTALLOGRAPHY. 



Ft and a mill- edged disc O, both immoTJiLly fijted to it The disc G is for tiimbg the 
gradunted ciivle round ; the use of the diuc F is to aaaUt in clamping it, which m 
effected by corapreseing the lower edgo of X^ between two plates of met^ S, T, tha 
former attached to the socket C, bj meaua of tb« screw U. A vernier R, att^bed by 
the metal strap Q U> the eot^ket C, servos to rend off the degrees on the cirdo E E. 
The axis which cwriefl thia circle and the discs F, G, w hollow, imd endoffes a thiancr 

Fiff, 359, 



J* ^ 



nxis which turns within it somewhat stiilly, nud camV-s at one ^nd the mUl-edg^d disc 
I, and at tho other fi bent brass rod K. Thm rod farrier a »!oeki*t L in which anothiT 
bent r«Hi M tumn, and in this is another tmoki^t N, tbrtmgh which passes n rod O O, 
which eaii l>e moved backwarila and fonvarda, and turned round by the disc P; at Ito 
other end of 1 1 mm rod the crjf^hil to Ito measured 18 fastened with wax. 

To iii^e thn inKtrumeiit, it is placed in front of a window with the phine of the cirde 
E vertical, mid at ri^htuiiglea to the plane of the window, the axes being then parallel 
to the horizoutid bars of the window, one cif which — or better, at^lit in it piece of black 
paper fastened to one of the panes^ may serve for the object x — to be rcHected from the 
planes of the crystal, Tbo observer, standing in front of the in^fraoient, may bring his 
eytj int*» such a position above the crystal, us to see a horizontal black line y drawn 
below the window, jnat along the edge of the crjslal ; and by turning thecrj'stal round 
by the disc P, he may bring one face of it into such a position ifmt the reflected image 
of the window-bar jr may just coincide with the liTje t/ tje*m directly. It is, however, 
absfilutc'ly necessary that -the edge of the crystal be brought exactly into a line with the 
axis of the inatrument. This mast first be done as nearly as possible by theunassistod 
eye : but to obtain a more exact adjustment, the crystal must bo turned, by means of the 
niovenjents at L and N, till the reflected image of the window-bnr seen from eodi face 
of the festal, is parsillel to the liney, that is to say. horiisontal The crystal is then pro- 
perly placed. To meawure the angle, the disc G is turned round till 180*^ on the divided 
circle E E coincides with the zero of the vernier ; the screw U is tightened so as to 
clamp the circle E E ; and the crystal is turned round by the disc I, till the image of 
s from one face coincides with the line y. The circle is then undamped, and turned 
r»3und b^ the dij5C G, till the other face of the crystal is brought into the same position. 
The division of the circle which is thtis brought opposite to the «ero of the vernier, 
gives directly the number of degrees in the angle contained beiwe«ii the two ^es of the 
crystd. (For othar forms of the reflecting goniometer, see DimctB Mincralog^y u 127.) 

When the faces of a crystal are bright and reflect well, a comparatively distant 
object^ sucli as the edge of the roof of an opposite hoiiHC, may bo viewed in them, and 
the angles may then bo me4isur*!d within a few niinutiH; t!io greater the diatanco of 
this object, the more exact, c*tirHif parihns^ will be the mensurement. With crystals of 
It^s reflating power, nearer olyeets, such as the \vindi>w-bars, mus^t bo chosen ; aome^ 
times indeed jt is necessary to use the flame of a cxindle phiced behind a screen having 
a Iioriscontal flit. Crystals whose siirfaces have little or no reflecting power maysome^ 
timi*s be measured with the refla'tlu^ L;uuiomcter, by attachijig to their faces very thin 



CUBAN — CUBEBS. 171 

plates of mica, by meam of water or oil of ttupentine, aocording to the nature of the 
crystal. 

Artificial aTstahi generally lose their lustre when touched with the hand, and will not 
bear cleaning. The best way of manipulating with them, is to fasten them with waiz 
by their dulleet surfiice to a uttle piece of wood, which may then be used as a handle, 
and for attaching them to the goniometer. 

It is important to obserre that the angles of crystals often change to a certain extent 
with change of temperature ; hence, for accurate measurements, the temperature should 
always be noted. 

A native sulphide of iron and copper, Cu*Fe*S" (see page 79). 

Pharmaeosiderite^ Siderite, Wurfderz, A variety of native arse- 
nate of copper occuzxing in crystals of the regular system, viz. cubes, sometimes perfect, 

sometimes having their edges or angles truncated, t,g, ooOoo . ooO {Jig, 195), ooOoo . -^ 

{fig. 198), and others. Cleavage cubic, imperfect The cube-faces are sometimes 
striated parallel to their intersections with the octahedral faces. Planes often curved. 
Rarely granular. Specific gravity — 2*9 to 3. Hardness » 2*6. Lustre adamantine, 
not very distinct. Colour olive-green to bladdsh-brown, also passing into grass-green 
ind emerald-green. Streak olive-green to brown, yellow, pale. Subtranslucent Bather 
•eetfle. I'yroelectric. (Dana, ii. 422.) 

When heated, it gives off water and turns red. Before the blowpipe on charcoal, it 
gives off arsenic vapours, and melts in the reducing flame to a erej sinning slag, whic^ 
gives with fluxes the reactions of iron and arsenic. Soluble in hydrochloric add. 
Caustic potash quickly turns it reddish-brown, and decomposes it for the most part 

An analysis by Beizelius gave 40*92 per cent As«0*, 2-67 PH)», 3990 Fe*0», 0*66 Cu*0, 
and 18*94 water (» 102*99 ; after deduction of 1*76 per cent matrix). If the small 
quantity of copper be regarded as Cu'AsO* and deducted, the remainder may be 
regarded as a tetrabasic ferric arsenate with 15 at water, in which ^ of the arsenic is 
replaced by phosphorus, giving the formula — 

4FeW3JJ^* + 15H»0; 

or 8[Fe«0».(Asi^^)«0» + 4n«0] + Fe«0».3n«0 
- 3[Ffe"'(As^PTr)o«.2H»0] + Ffe'"H»0», 

in which the first member has the form of Scorodite. (Kamm. Mineralcb. p. 372. ) 

Cube-ore was formerly obtained from certain mines m Cornwall, where it occurred 
coating cavities in quartz, with ores of copper. It is now found in small shining 
erjstau at Bundle Gill, Cumberland ; also in Australia ; at St. Leonard in France, 
a»l at Sdineeberg and Schwarzenberg, in Saxony. 

CTJBBBA CZpinilZ BKZQ. The fruit of the black pepper of West Africa, called 
Bprr caudaiunu According to Stenhouse (Ann. Ch. Pharm. xcv. 106), it contains 
piperin and not cubebin, so that it must be regarded as pepper, not as cubebs. 
An isomeric modification of oil of cubebs (p. 172). 
C"H**C)*? (Souboiran and Capitaine, Ann. Ch. Pharm. xxxi. 
190. Riegel, N. Jahrb. Pharm. viil 96. Schuck, N. Repert. Pharm. i. 213.) A 
crystalline substance existing in cubebs. It is obtained by exhausting with alcohol 
the pulpy residue left after the preparation of the essential oil of cubebs, treating 
the alcoholic solution with potash, washing the resulting precipitate with water, and 
crrstallising from alcohol (Soubeiran and Capitaine"). — Schuck prepares cubebin by 
mixing cubebene with } of its weight of quicklime, exhausting with alcohol, treating 
the evaporated extract with dilute potash, dissolving the residue in alcohol, decolo- 
rising with animal charcoal, and leaving the solution to crystallise. 17 oz. of cubebene 
thus treated yielded 15 grains of cubebin. 

Cubebin crystallises in groups of small white needles. It is tasteless, inodorous, 
melts at 120^ C. ^Schuck), but cannot be volatilised without decomposition. It is very 
slightly soluble in water and in cold alcohol, more soluble in boiling alcohol, the 
solution solidifying to a [)ulp on cooling. Ether tlissolves 375 i)er cent, cubebin at 
12^ C, and more when heated. Cubebin also dissolves in acetic acid, and in oih» both 
filed and volatile. Strong sulphuric acid first colours it of a fine bripht red, very 
much like that which it imparts to salicin, but afterwards changing to crimson. 

OUMMBM* The fruit of Pij>*r Cufnfta, L., a native of Java. When dry, it forms 
roundish blackish-grey berries of the size of pepper, enclosing a hard white oily seed. 
It has an aromatic peppery odour, and a sharp bitter taste. According to Monheim 
(J. Chim. m^ zi 352^ it contains 2*5 per cent, green volatile oil, 1*1 yellow liquid 



172 CUllEBS, CAMPIIOK 0F_CUL1LABAN, OIL OF. 



oil, 6*0 cubebiu^ 15 bulHamie rcain, 3'0 waxy mat &^i 6*0 extmctiTe mutter, 1-5 cbloride 
of sodium^ aud 64*0 woodv fibre, 

dTBlfillB, CAMPHOR Ol*. (BUnc lipt ami Sell Ann. Cli. Pharm. Ti» 294.) 

- Stmr^pUttf^ qf Oil of Cnhtits. The valutile oil of cttbelift, after rectifieutlon with water, 

m clepo^kits tbb compound in rhombic crjHtjds P . oP . adP, in which P : P in the terminal 

f Cilgcs ssll6^4{l' and 1&^ 'l\\ and in the lateral edg«s fel45°* Clcarago perfbct, 

parulWl to oP. It mella at 08*^ C.^ boils at 150*=*, and distils without alteration. It is 

insoluble in wiiter, soluble in alcohol, ether, and volatile oils. The alcoholic eolutiou 

posaesse!! opticid rtitatory power» 

According to Blanche t and SelPa analjaes, the camphor cootabs froTn 80*1 to SI*1 
per cent, crtrbon, and 111 to 117 hytogen, agreeing approxiraatidj with the forranla 
C^*H^O Of C^*ir'.H*0, whence it appears to bo ft hydrate of oil of eubeba or of 
cnbebene. 

The camphor dissolves in fltronR aulphuric acid, forming apparently a comngutcd 
arid. It is partially FoUible in Ixiiling jMtash* By nitric acid it is converted into a 
brown rei*in ; by cldorine into a viscid stibstauce. 

CfraUBS, on. or, C'*II»*. (Mullen Ann* Ch, Pharm. ii. 90, Blanchet 
and Sell, ihid, vi. 294. W i n e k 1 e r, thid. viii. 20S» S on b e i r a n and Capitame, ibid, 
Mtxiv. 311. Anbergier, Rev. «eient. iv. 220* Brooke, Aonala of Philowphy, 
new series, v, 450. Oerh. iii. 634.) Tliia oil is obtained by distilling cuWbs with 
water. It is colourless, viscid, of Bpeeiftc gravity 0U29, bas an aromatic odour, and a 
camphor-like epicy taste. It boils between 260^ and 250** C, always, however, with 
partial decomposition. Exposed to the air^ it l>ecomes thicker and resinous. It turns 
the plane of polarisation of n luminous ray to the lefL 

H^droehloraic of oil of cube be, C^Jl^^,2KClt h produced by paasmg hydro- 
chloric acid gas into the rectified oil. It forms fddique prisms, colourless*, taateless, 
inodorous, melting at 131^ C, very soluble in.alcohot They turn the plane of pola- 
miition to the ML 

CuMirnr^^Oi] of cuheba di.stilled with sulphuric acid is converted into an isomeric 
oil, cube bo lie, possessing luucli less optical rotatory power than the original oil 

Cirsxorf £, Syu. with AxiJjCiMB (i. 210), 

CtraiXOSS* A constituent of the edible birda* nests of India, exhibiting the 
general properties of the neutral albtimijioida, (Pay en, Compt rend. zliz. 628.) 

CtTBOICXTE, %n. with Cbadastte. 

OITBOZTS. Syn. with AsAucfsc^ also with Sodalite. 

crvciniEXS. A genus of cucnrhitaceous plants, including the cucumber, melon, 
and sOTixc kindi* of gourd. 

The fruit of Cttcmmb coforynihi^^ the Iiitter appl<*i or colocynth gourd, contains a 
pulp or pith which, when separated from the seeds, couiititutes the purgative drug 
colocynth. (See CoLOCTSTHtK, p. 78.) 

C melo^ the melon, has been examined by Pay en (Bucbu. Repcrt. hcvi. 104) t it e<m- 
tjiins the usual vegetable constituents. The root contains, accortling toToroisiewica 
{ihid. xlv. 1), an emetic principle, melonemetin ; and yields 6*4 per cent of ash, d 
which 5 per cent, consists of salta soluble in water, and 95 per cent, insoluble matter. 

The fndt of C propfutarnm contains, according to "Winckler, a bitter principle, 
which, ftccordiiig to Wak, is essentially a resin {Proph€tinharz\ containing C^H^O', 
separal>le mhj pri^phtkrin or prophrtdnt C*H**Q*, aod a carbohydrate (glucose). 

ClTCJmLBZTJi* Another genus of cucurbit aceous plants, induding the common 
gourd, C. maxima, with its numercms varieticfl, the vegetable marrow, C. omfrroy the 
orange gourd, C. aurantia, the squasli or bush gounV C, tntloprpo^ the bottle gourd, 
C. la<fn}oHa, &c. &c. Most of them are eatable ; but the orange gourd is bitter, and 
the bottle gourd is & dangerous jjriison. The fruit of this last-mentioned speeics, how- 
ei-er, eontiuus, according to Marquardt (.T. pr. Chem. xi. 500), about 6 percent, of 
sugar, and is used in Hungary for the extraction of sugar. The seeds contain a mild 
fixed oil.— The water-melon. C, eitm/lM, has been examined by Lauderer (Buchn. 
Bopert IxvL 104). Len^jble (J. Pharm, [S] ii. 3o6) found in it 3 per cent vugar, 
30 per cent* residue, and 67 water. 

Ctn&limi^S. Sec Archil (i. 355). 

OV&XB&IXB* A name sometimes given to a mineral from Oulehras in Mexico, 
resembling Kiolite, and said to consist of selenido of tiac and s:ulphide of mercuiy. 
(Haadw. d. Chem. ii. [3] 235.) 

CPXIIiilBAlf or CJJJ^iaLVirAW, OI£ OV. A volatile oil obtained from the 

bark nf fMf'rtis Ctdthhtin or OtJ^famtUi, or Ctnnamoimtm Culifawan (Nees), a nattTe of 
rlio Moha-iiisi, by distillation with Mater. It is colourieas; smelhi like oil of cajeput 



d 



CUMENE. 173 

and oil of doree ; ia hearier than water ; dissolres, with red colour, in nitric add, 
forming a aolntion from which water throws down a brick-red resin (S c h 1 o s s). Heated 
with 6 parts of fuming nitric acid, it swells up strongly, gives off nitrous gas, and, 
when repeatedly distilled, yields oxalic acid, amounting to } of the oil. (G m. zvi. 364.) 

CUBBXVa. Cfumol, Hydride of Chtmenyl (?H" « C»H".H. (Pelletier and 
Walter [1837], Ann. Ch. Phys. [2] Ixvii. 99. Gerhardt and Cahours, Ann. Ch. 
nrjTB. [3] L 87, 372 ; Ann. Ch. Pharm. xxxriii. 88. Gerhardt, Ann. Ch. Phys. [3] 
xiT. 107. Abel, Ann. Ch. Pharm. Ixiii. 308 ; Mem. Chem. Soc. iii. 441 ; Phif. Mag. 
zzziL 63. Cahours, Compt rend. xuT. 657, xzx. 321. Mansfield, Chem. Soc. Qu. 
J. L 244; Ann. Ch. Pharm. box. 179. Gerhardt and Li^s-Bodart, Compt. rend. 
itxiT 506; Compt. chim. 1849, 385; Ann. Ch. Pharm. Ixxii. 293. Ritthausen, 
J. p. Chem. Ixi 79. Church, Phil. Mag. [4] ix. 256. Liis-Bodart, Compt rend, 
xliu. 394 ; Ann. Ch. Pharm. 100, 352. Warren do la Rue and H. Muller, Chem. 
Gas. 1856, 375; J. pr. Chem. Ixx. 30. 

This body, discoTcred by Gerhardt and Cahours in 1840, is probably identical with 
the rc«in-o& or retinyl obtained by Pelletier and Walter from the resin of Pinus 
mariiima (see Pinb-besins), and probably also with the hydrocarbon produced by the 
action of phosphoric anhydride on phorone. It is isomeric with mcsitylene, with 
metbol, ana witn a hydrocarbon discovered by Church among the products of the dis- 
tillation of eugenate of barium. 

Camene exists ready formed in Burmese naphtha, that substance, when aqueous 
rapour at 200^ C. is passed through it^ yielding hydrocarbons from which sulpho- 
comenic acid is produced by the action of oil of vitriol (Warren de la Rue ana H. 
Muller). It is produced : 1. In the distillation of cuminic acid with excess of baryta 
(Gerhardt and Cahours). — 2. In the dry distillation of the resin of Pin us mariiima 
(Pelletier and Walter) ; of the wood of that tree, passing over into the crude spirit 
(Cahours); and of coal, bein^found in coal-tar naphtha (Mansfield, Ritthausen, 
Church). — 3. In the distillation of phorone with anhydrous phosphoric acid. (Ger- 
hardt and Li^s; Li6s.) 

Frfparation. — 1. Froin Cuminic Acid, — 1 pt. of cuminic acid is gradually heated 
in a retort with 4 pts. of baiyta. When the heat is carefully applied, and not more 
than 6 grammes of cuminic acid are used, nothing but colourless cumene passes over, 
vhile carbonate of barium remains behind. The use of larger quantities at once is 
not to be recommended (Gerhardt and Cahours). Abel mixes cuminic acid with 
4 pts. of lime, and heats the mixture nearly to redness in a copper retort placed in a deep 
sand-bath. The colourless distillate has an unpleasant empyrcumatic odour, which it 
retains even after rectification over hydrate of potassium. Abel therefore distils it 
witli concentrated chromic acid (which does not alter the cumene), distils (whereby 
the bad smell is completely destroyed, and the pleasant odour of cumene becomes per- 
ceptible), and dries over chloride of calcium. 

2. From ike Beein of Pinus mariiima. — When the brown oil obtained in the prepara- 
tion of illuminating gas by the dry distillation of this resin, is subjected to fractional 
distillation, benzylene passes over between 130° and 160^ C., and then cumene. The 
latter is severaJ times distilled, with separation of the first portion of the distillate, 
which eontains toluene, then treated alternately with oil of vitriol and caustic potash, 
and each time distilled, and finally rectified two or three times over potassium. (Pelle- 
tier and Walter.) 

3. From Light Coal-iar Ntmhiha^ passing ovor between 140° and 145° C. (Mans- 
field) ; between 139° and 140^ (Ritthausen). — It exists in the naphtha in consiaerable 
quantity, and may be advantageously prepared therefrom. 

4. From crude WoodspiriU — ^When the oil separated from this liquid by water is 
shaken up with oil of vitriol, washed with potash-ley and water, dried ovor chloride of 
calcium, and distilled over phosphoric anhydride, and the portion which distils between 
140° and 150° C. is subjected to fractional distillation, cumene passes over between 
145° and 148°. (Cahours.) 

Properties, — Cumene is a colourless strongly refracting oil, having an agreeable odour 
like that of benzene, and a pungent, somewhat bitter taste. Specific gravity 087 
(Pelletier and Walter). Boils at 144° C. (Gerhardt and Cahours) ; at 148° (Abel and 
Cahours). Vapour density — 4*0 io 4*3 (obs.); 4*16 (calc 2 vols.). Its compositioa 
is shown in the following t^ible : 

r^h^i^ti^ Pelletier and Gerhardt .y. , ,». 

CaleutatUni. Walter. and Cahourt. ^*^- *'*^** 

C» . .108 90 89-48 8981 90*34 8857 

H»« . • 12 10 1008 9-97 9-88 10-28 

C»Hw . . 120 100 99-56 99*78 10022 98'8& 



174 



CITMENE— CUMENYLAMTNE. 



Cumene is insolublo in wntfr, but disaolrcs readily in rmo^'Spirit, al^^hol^ rfftfr^ and 
rolatiU oiU, It combines yi'iXhJiTfd oiis^ JaU, and moat resins. Willi the aid of heat 
it dissolTea 9uiphur, which crj'atalHseB out on ctioling ; it also diflsolros iodine. 

Jkcompositiofis. — 1. Cumene m conrerted by fuming? sidphuric acid into snlpho- 
cmnenic acid (Gtirhanlt and Cahours), — 2. When chlorine is passed iiit4> b<:>iline; 
camene, and the volafiliscd portion is cohobated, a thick fainl-BmelliDg oil i^ obtainoi 
which bums slowly vnih. a smoky greeji-edgivl flame ; its vapour does not attack the 
cyps (PDlli^ticr and Wult<*r). — 3. By fuinlng nUric acid^ it i« converted into nitro- 
cumtiie (Cahotirs, Nicholson), also by l>oiliug with strong nitric acid, but by continnctl 
boiling it fonm? a peculiar acid (Gcrhordt and Cahoura), If the l>oiling be continued, 
the nitroeumene disappears again, and is gnidually converted into a yellowijsh 
crystalline imasSf which dissolves in ammonia, ^rith the €;?3Eception of a small pulve- 
rulent residue, Hydrocliloric acid added to the solution prwipitates nitrobenzoie 
acid (Abel, Cahours). Dilute nitric acid converts cumene^ after four or five days' 
boiling, into benzoic acid (Abel). — i. A mixture of /ttming nitric and fuming nui- 
phuric acid slowly cooTcrts ciimene into dinitjocumene (Cahours). — ^5, Potassium kept 
for some time iu contact with cumi^tie, blackens and becomes covered with a black 
crust, which appears to bo carbide of potassium (Pelleticr and Walter), Cumene is 
not altered by potaah-Iey or by jfiased pataih. 

Vltrooumeae. C"H"(NO='). (C a hours, Compt, rend- xxv. 652, xxri. 315. 
NicholBon, Chem. Soc, Qu. J. i, 2. Eitthaueen^ J. pr. Chom. Lti, 79.) — VThcn 
camene is dissolved in fuming nitric acid^ the mixture becomes hot and givcM off 
abundance of rod vapours, and on adding water to tho liquid, nitroeumene in precipi- 
tated as a heaTV oil. It is yellowish, and has a fainter and less agreeable odour than 
nitrobenzene. By sulphuretted hydrogen in presence of alcohol and anuuouia, it is 
converted into cumcnylamine. 

I>liiltrociLitieQ«. C*H^*(NO*)*. — Obtained by treating cnmene with a mixtnre of 
faming nitric and fuming sulphuric add. The action takes place with difficulty, and 
requires frequent renewal of the acid to complete it* 

Dinitrocnmene crystallises from akobol in white laminae It is insoluble in caustic 
alkaline leys, bat disiolves in alcoholic potash and is converted thereby into nit ro- 
be n/^ylene ; hydrochloric acid added to the solution throws down brown dakea. (Ca- 
hours, RitthauBcn^ t&c. cil.) 

CUSKSlfS-SV^f SlfBZO ACIB< See CuvEXTL-suLP^unors Actn. 

OU MJUlf CITlSi A crystallised mineral from the province of Constantine in Africa, 
containing, according to Cumenge (Ann. Min. [4] xx. 81), 20 at, antimony, 21 at, 
oxygen, and 16 at. water. Ramni els berg { Miner alchrmie^ p, 166) suggMti that tt 
mny be a hydrate of antimomc acid, S1>'0».4H=0 (or 2H'SbO*.H'0). 

CtFMXirTlM C^H". — A tnonobasic radicle which may be suppo^ to exist in 
cumene, cuminic acid, and many allied compounds. Thus : 

Cumene (Hydrate of Cumenyl) . . . . . = C»H^'.H| 

Cumidine (Cumenylamine) = C«II*'.IP.N 

Cumonitrile (Cj jinide of Cumenyl) , , . . ^ C*H",CN 

Cumene-sulphurie or Sulphocunienic acid (Cumeuyb { ^ C"H^MI J qj 

Bulphurous acid) ......{ ~ (80**) { 

Cuminic or Cymylic Alcohol . . . . . = H ( ^ 

Cumyl = CO,C«H" 

CO C?*H*' t 
Cuminic Aldehyde or Curoinol = H f 

Cuminic Acid . . . . * ,.. .= H( 

It will bo seen from these formula?, thtit cumenc, cuminic^ alcohoi euminol, and 
cuminic acid are related to one another in the same manner as marsh-gas, ethylic 
alcohol, acetic aldehyde, and acetic acid. 

The name eftair-nyl has also been applied to C"*H", the radicle which ia to cymylic 
alcohol as ethyl to common alcohol ; but this creates confusion. 

CxnMTEirsx^AJaiia'B. Cumidiiie, C'H'^N - NJP.CH". Cahours [18471, 
Compt rend. xxiv. 5o7 ; xxvi. 315; xxx 321. Ed, Chambers Kicbolson^ Ann. 
CIl Pharra. Ixv. oH\ Chem. Soc, Qu. J, i. 2, A. W. Hofinann, Ann. Ch. Pliana* 
Ixvi. 146; Ixxiv. 15. Kitthauson, J. pr. Cbem. Ixi. 79. Church, PhlL Mag, [4] 
ix 454.) 

Formation, — By the action of aulpbydric add on nitroeumene, CH*'(NO'), in 
preeenoe of alcohol and ammonia. 



I 
I 
I 



CUMENYLAMINE. 175 

IV fparatum. — ^Nitrocameno is dissolved in alcohol, and the solution is saturated, first 
vith ammonia, then with sulphydric acid. After a few days, when a large quantity 
of Bolphnr has been deposited and the odour of sulphydric acid is no longer per- 
orotible, the gas is again passed through the solution and the liquid is distilled, 
whereby the decomposition of the sulphydric acid is accelerated ; and this treatment 
is repeated till the whole of the nitrocumene has disappeared. The alcohol and 
sulphide of ammonium are then removed by distillation ; the residue is dissolved in 
hydrochloric add ; the liquid filtered from the sulphur is evaporated till it solidifies in 
a ciystalline mass on cooling ; and the boiling solution of hydrochlorate of cumenylamine 
is treated with potash to separate the base, which rises to the top of the liquid as an 
oily layer. This oil is rectified and supersaturated with a concentrated solution of 
oxalic add ; the liquid is evaporated to dryness ; the residue dissolved in boiling 
alcohol ; and the solution treated with blood-charcoal ; the filtrate, on cooling, deposits 
perfectly pure colourless prisms of oxalate of cumenylamine. This salt is dissolved in 
water ; the solution decomposed by potash ; and the layer of oil which rises to the 
snr&co is removed with a pipette, dried over chloride of calcium, and rectified. 
(Xicholson.) 

Properties. — Pale yellow, or, when recently distilled, nearly colourless oil, of specific 
sravity 0-9526. Refracts and disperses light strongly. When cooled by a mixture of 
loe and salt, it solidifies in a mass of square plates, which quickly melt again as the 
temperature rises. Dropped upon paper, it forms a grease-spot^ which gradually dis- 
appears. In contact with platinum-wire, it boils constantly at 226^ C, when the 
barometer stands at 0*761 met. It has a peculiar odour and burning taste. Neutral 
to turmeric and red litmus paper. Colours fir-wood intensely yellow (like phenyl- 
amine and benzylamine), but does not exhibit the reaction of phcnylamine with 
ehloride of lime. It dissolves very sparingly in water ; very easily in sulphide of 
earbon, wood-spirit, alcohol, ether, and fat oils. (Nicholson.) 

Dfcompasiiions. — 1. Cumenylamine exposed to the air^ even for a few minutes only, 
tnmfl yellow and then dark i«d, especially if warmed. — 2. The vapour bums with a 
yellow, very fuliginous flame. — 3. It is violently attacked by chlorate of potassium and 
j^rocJUoric ad^ and converted into a brown viscid mass, which smells strongly like 
trichlororophenic add, and is dissolved by alcohol, leaving a residue of chloraniL — 
4. Bj bromine it is converted, with rise of temperature and evolution of hydrobromic 
addv into a solid mass, which is insoluble in water, but soluble in alcohol and ether, 
oystallifles in white needles, and is perhaps tribromocumenylamine (C*H"Br*N). — 

6. Strong nitric acid dissolves cumenylamine with splendid purple colour, and water 
added to the liquid throws down flakes which appear to be an acid. — 6. Dry chromic 
add becomes very hot in contact with cumenylamine, but does not set it on flre. — 

7. In phosgene-gas, cumenylamine is immediately converted into a crystalline mass, 
which se^rates from alcohol in lon^ crystals like nitre ; probably dicumenylcarbamids 
N*.H*^C*fl")*.(CO)'', homologous with diphenylcarbamide or carbanilide. — 8. Cume- 
nylamine dissolves in sulphide of carbon^ and then gives ofif a large quantity of 
tolphuretted hydrogep ; water added to the solution throws down, after a long time, 
a quickly solidifying oil, which crystallises from alcohol in long needles ; probably 
dieumen^lsulphocarbamide, N«.H«.(C»H")«(CS)" (Nicholson).— 9. When dissolved in 
water, it is converted by cyanogen gas into cyanocumenylamine (Hofmann). — 
10. With eyanate of phenyl, it immediately solidifies to a solid ciystallino mass. 
(Hofmann.) 

Salts of Cmnenylamlne. Cumenylamine is a ver^ weak base. It predpitates 
seaquioxide of iron from ferric salts. It does not precipitate alumina or zinc-salts. 
Its salts crystallise veiy easily, and, with the exception of a few double salts containing 
chlorides of the heavy metals, they are colourless, but turn reddish on exposure to the 
air, or when dried at a very high temperature. They have an add reaction and are 
anhydrous, like the salts of phenylamine. From concentrated solutions of cumeny lamine- 
salts, alkalis separate the cumenylamine in dark oil-drops, and from dilute solutions 
in the form of a curd. All the salts of cumenylamine dissolve in water, but better in 
alcohoL (Nicholson.) 

Acetate of Cumenylamine crystallises readily. 

Hydrobromate of Cumenylamine crystallises readily. 

Hydrochlorate of Cumenylamine, C*H»*N.HCL — The combination of cume- 
nylamine with hydrochloric acid is attended with evolution of heat. The salt crys- 
tidlises from water or alcohol in large, colourless, inodorous prisms, which turn red in 
the air when moist. It does not undergo any alteration at 100° C, but melts and 
snbh'mes when strongly heated. 

Chloroplatinate of Cumenylamine, Cir'N.HCJLPtCl'.— When a warm aqueous solu- 
tioQ of hydrochlorate of comenylamiue is mixed with excess of dichloride of platinum. 



176 CUMENYL-SULPHUROUS ACID. 

the liquid, on cooling, deposits long yellow neodles, which may be obtained pore by 
washing with cold water. The salt is decomposed by boiling water. When heated 
fer se to 100^ C, it becdmes darker, without farther alteration, and at a stronger 
neat, gives off hydrochlorate of cumenylamine, and leaves platinum. Alcohol dissolves 
it in krgo quantity ; and the solution yields, after a while, dark red oil-drops, which 
solidify, after the alcohol has evaporated, in a crysUllline mass of a splendid orange- 
yeUow colour. 

With Protoehloride of Palladium, hydrochlorate of cumenylamine forms a double 
salt, resembling the chloroplatinate in appearance. 

Sulphate of Copper forms, with alcohohc cumenylamine, a precipitate of & fine green 
colour. 

Protochloride and Cyanide of Mercury form, with alcoholic cumenylamine, white 
crystalline precipitates which are decomposed by boiling water. 

With Trichloride of Gold, alcoholic cumenylamine forms a violet precipitate, which 
dissolves with violet colour in a larger quantity of alcohol. 

Hydrofiuate of Cumenylamine crystallises. 

Hydriodate of Cumenylamine crjistalhsea readily: it appears to be the most 
soluble of the cumenylamine salts. 

Nitrate of Cumenylamine, C*H*'N.HNO*. — ^When cumenylamine is dissolved 
in dilute nitric acid, the liquid becomes filled, on cooling, with long needles, which are 
colourless if the acid used was not too strong. The salt remains unaltered at 100^ C. 
It is soluble in water aod in alcohoL 

With oxalic acid, cumenvlamine forms a neutral and an acid salt^ which are both 
cxystallisablc, but cannot be separated. By dry distillation, they yield a slightly 
crystalline mass, which dissolves sparingly in alcohol, and exhibits the relations of 
oxycumenylamine. (Nicholson.) 

Phosphate of Cumenylamine crystallises readily. 

Sulphate of Cumenylamine, 2C*H"N.H*S0*. — ^When cumenylamine is dissolved 
in boiling dUute sulphuric acid, the solution, solidifies, on cooling, in a crystalline mass, 
which mav be obtained perfectly pure by recrystaUising with animal charcoal. In- 
odorous; has an unpleasantly bitter taste. At 100^0. it gives off the odour of 
cumenylamine, and assumes a reddish colour, without farther alteration. Dissolves 
sparingly in cold water, much more readily in alcohoL 

Osranoonmenylamiiie. C»It»«N.CN, or 2C"ir"N.Cy*.— An alcoholic solution of 
cumenylamine saturated with (^anogen quickly deposits long needles of cyanocume- 
nylamine, which are cosily pureed by crystallisation from ScohoL This substance 
forms, with hydrochloric acid, a salt nearly insoluble in water. (Hofmann, Ann. 
Ch. Pharm. Ixvi. 146.) 

VttroenmenjteiiilBe. CH*<(NO*)N. (C ah ours, Compt rend. xxiv. 557 ; xxvL 
315.)*— Prepared by treating an alcoholic solution of dinitrocumene with sulphide of 
ammonium. It forms yellow ciystalline scales, which melt below 100^ C, and solidify 
in a radiating mass on cooling. The compound exerts a slight but distinct alkaline 
reiibtion on test-paper. It is insoluble in water, but dissolves readily in alcohol and 
ether. 

It is partially decomposed by distillation ; nevertheless the greater part passes over 
unaltered. — Bromine acts violently upon it, converting it into a crystallioe product^ 
which is no longer basic. — It is not altered by chloride ofbenzoyLtLt ordinary tempe- 
ratures; but between 50^ and 60^ C. it is converted, with violent action, into a ciys- 
talline product^ which, when dissolved in alcohol, after being washed with acid, 
alkaline, and pure water, crystallises in snow-white needles, containing C'H'^N'O'a 
N.(C'H*O.NO'.C*H"), nitride of benzoyl, cumenyl and nitryl, corresponding therefore to 
benzamide and benzanilide. — With chloride of cumyl and chloride of cinnamyl, it 
forms products similar to that with chloride of benzoyl 

Nitrocumen^lamine neutralises acids completely, even the strongest, formine salts 
which crystallise well. These salts, if exposed to air in the moist state or in solution, 
decompose quickly, assuming a greenish-blue colour. 

The sulphate, 2C»H«(N0«)N.H«S0* + aq., is obtained by dissolving nitrocume- 
nylamine m hot dilute sulphuric acid, and leaving the solution to cool slowly. Long 
needles having a strong lustre. May be pulverise<l. 

Hydrochlorate. — The saturated solution yields, by slow cooling, white silky needles, 
which, in the dry state, are composed of C*H'*(N0«)N.HC1 + aq. 

The oxalate forms slender needles. 

OUaonrsX-SirXiPSmtOinBI ACZB. Cumene-sulphuric, Sulphoeumenic, Sul- 
phoeumolic, or Sulphocumenyiic acid. (?R^*SO* ^ ^^^XjAo\ (Gerhardt and 



CUMINAMIDE. 177 

C ah ours, Aim. Ch. Phys. [3J L 90.)— This acid is produced by the action of ftiming 
sulphuric acid od cnmene. It is not known in the free state, but the barium-salt may be 
prepared as follows : — 2 pts. of fuming oil of vitriol are poured upon 1 pt of cumeno in a 
glass cylinder, and the liquid is stirred till the whole of the cumene is dissolved. When 
Lige Quantities are used, the whole may be left to stand in a closed vessel, the cumene 
then dissolying gradually. The dark-brown solution is diluted with 4 volumes of 
water, whereupon, if the cumene and the acid have been long enough in contact, a 
eolourless solution is formed, without separation of cumeno ; and the liquid, saturated 
with pulverised carbonate of barium, then filtered and evaporated, yields, on cooling, 
cumenylsulphite of barium. The colourless mother-liquor yields, to the last drop, the 
same ralt^ which may be obtained pure by pressure between paper. 

Cumenylsulphite of Barium, (7H"BaS0', forms very beautiful scales, having a 
atzong pearly lustre. It dissolves very easily in water, especially when hot. It is 
■olabfe in alcohol, even in anhydrous alcohol, and likewise in ether. 

The aqueous solution does not precipitate chloride of cadmium, neutral acetate of 
lead, or the salts of bismuth, nickel, copper, or mercury. 

CrUBOCmi A name sometimes applied to the radicle of cymylic alcohol, 
C»H».H.O. 



Vf OI& OV. A volatile oil obtained from the seeds of Cuminum Cj/minum 
by extraction with absolute alcohol and precipitation by water. It is a mixture of 
cmninol (p. 182) and cjrmene. 

IC ACZ2>. See Oxtcuionamic Acid (p. 179). 

»B or CVMTZJLMZBB. C>«H"NO = N.mG>»H"0. (Field, 
Ann. Ch. Pharm. Ixv. 46.) — This compound is obtained by the action of heat on 
eliminate of ammonium : 

C»«H»(NH<)0» - mo = C'»H'*NO, 

or by the action of ammonia on cuminate of ethyl, chloride of cumyl, or cuminic an- 
hydride. Like benzamide, it crystallises in two different forms, according to the 
manner in which it is deposited. By rapid crystallisation from a strong solution, it is 
obtained in highly lustrous tables, whereas a dilute solution deposits it in long opaque 
needles. It dmsolves sparingly in cold water, easilv in alcohol and in ether. It offers 
considerable resistance to the action of strong alkabs, and requires long boiling with an 
acid or an alkali to convert it into ammonia and cuminic acid. 

Cumophenamide Gt Cumanilide, C'«H"NO = N.C"H"O.C«H*.H, is produced 
by the action of chloride of cumyl on phenylamine. The mixture becomes very hot, 
and ciimophenainide is formed, which, when purified by washing with water and crystal- 
liaation fix>m alcohol, in which it dissolves but sparingly, forms long satiny needles, re- 
sembling benzoic add. (Cahours, Ann. Ch. Phys. [3] xxiii. 349.) 

Cumth9ulphophenamide, C"H"NSO»= N.C"H»O.C«H*SO^H. (Gcrhardt and 
Chiozza, Ami. Ch. Phys. [3] xlvi. 151.)— Sulphophenamide treated with chloride of 
cumyl in the oil-bath at a moderate heat is rapidly attacked, and on cooling solidifies 
to an amorphous glassy mass, which may be crystallised from alcohol. If the tem- 
perature were allowed to rise too high, cumonitrile and sulphophcnic acid would be 
produced. 

The compound forms rectangular prisms with shining, well-developed terminal faces. 
It is insoluble in boiling water, but dissolves easily in cold and still more in hot 
alcohol, easily also in aqueous ammonia. It melts at 161^ C. When quickly heated 
in a test-tube, it gives off cumonitrile. 

Cumo-8ulphophenargentamide^ N.C"H"O.C*H'SO'.Ag, is obtained by adding 
nitrate of silver to a solution of cumo-sulphophenamide in boiling water contaiuing a 
few drops of ammonia. It forms very liglit slender needles nearly insoluble in boiling 
water, easily soluble in ammonia. Decomposes quietly when heated, giving off cumo- 
nitrile. (Gerhardt and Chiozza, loc, cit.) 

CumO'Sulphophen-argento^iamide, N«.H*.Ag.C«H»SO«.C'«H"0, is obtained 
by dissolving the preceding compound in ammonia, and leaving the solution to eva- 
jtorato. Ciystallisea in nacreous needles, grouped like a fan. Soluble in alooliol, very 
riightly soluble in water. When boiled for some time with water, it gives off a little 
ammonia. 

CumO'hengO'8ulphophenamide, C«H«'NSO« - N.C'«H'»O.C'H»O.C«n»SO«. 
Forme<l by the action of chloride of cumyl on benzosulphophenargentamido (i. 640), and 
obtained in confused prisms by dissolving the product in hoiling ether and evaporating. 
It is nearly insoluble in water, more soluble in alcohol, sparingly in ether. Am- 
monia dissolves it with difficulty, the solution being precipitated by acids and by the 
aalta of lead and silver. (Qerhardt and Chiozza, loc. cit,) 

Vol. II. N 



178 



CUMINIC ACID. 



Cumo'salieylamide, C'*H"NO» = KC'"H'^O.C'H'O^H ?— Obtained by tho 
action of chloride of cumyl on Balicylamidc. Crj^stalliaes in very light aliining needles* 
nif^ltmg At 20U° C, beconiiug pasty st a Htrotiger heat^ and rrmuitiiiig bo on ccH^ling. 

CtratXn^C acid. Om'H)* ^ C»»H"O.HA or C^H'^O". (Gerbardt and Ca- 
hoTirs [1840], Add. Cb. Pliys. [3] i. 70. Gm. xir. 148.)— This acid m produced by the 
oxidation of the oxygenated oil (hydride of cuinyl) contained in efUicnce of ctunin. 

Prrparation. — Hydrido of cumyl ia added drop by drop to potash in the state of 
fbsrion, whereupou hydrogen i§ eyolvtHl and cuminnte of potoftaium is formed ; and this 
salt, dkeolved in crater and de(^:imjx>s*d by nitric acid^ depositif cumlnic acid, which 
may be purified by crystalliKation from iilcohoi 

The formation of cuminate of pottiasinm in this process ia represented by the 
equation : 

C«H'*0 + KHO = C»»H»'KO + H* 

Hyclridciaf Curnlnaleof 

JV»>pef /w*, — ColourleBs prismatic tables, having & pure acid taste and an odoiir 
■omefwhat like that of bugs. It melts at 92^ C„ and Tolatilisea at about 26(P. It is 
nearly inaolublc in cold water, but soluble in alcohol and ether. When pure, it dissolves 
without colour in introug sulphurie acid, 

Dtvompasitions. — 1. Fuming nitrw add coDTert^ cumin ic add into nitrocnmiaic 
acid ; with a mixture of nitric and tuiphuric acid», it yields dinitrocnminic acid, 

2. By dry distillation with baryta or ItTfit, it ia resolved into cMuone, C*H'-, and car- 
bonic acid : 

Ci«H"0' + BaK> = C^n** + I5tt«C0\ 

3. With pnitacht4>ride of phosphorite, at a tjemperature not exceeding 50*^ or 60° d 
it yields oiy chloride of phoHphorus, chloride of cum jl, and hydrochlorie aeid: 

C'"H»'O.H.O + PCRCl* = PCm + C'*H"0.C1 -f HO. 

4. OxycMoride of phosphortta converts cuniinate of sodiniti into oumini canhydride 
(Gerhardt). — 6. Cumiuic acid boiled with acid chrojnatc of potassium and sy/pkuric 
acid IS converted into insolinic acid, C"H*D* (Ilofmann, Ann. Ch. Pharni. xlvii* 
197). — 6. Cununate of potassium heated with br&midc of ct/anogen yields cumonilrile 
and bromide of potassinrtL — 7. The sodium-salt heated with cmoride ofcumyl^ Q^t^f, 
or Inmoyf^ yiehis cuminic, acetocuminic, or beiizocuminic anhydride (Gerhard t)u — 
8. Cumiuic acid doi^ not undergo any transformatioD in pusaing through the amiual 
orgaiii^ra^ but is found iJi the iinne on altered. 

Cu »iyATBS»— Cnminic acid is mooobasic, the formula of it« salts being C"H*'MO". 

Cuminatf of ammonium forms delicate tnfta which lose their lustre when exposed to 
the air. When heated^ it gives up the elements of water and ^'ields cuminamido and 
cumonitrile. The potas&iutH-saH iH deUf|uescent, and cannot be obt^dned in regular form. 

CuminaU of fmrium^ C'*H"BaO^ l* obtained in dazzling white nacreous scales by 
decomposing carbonate of barium with a eolation of i^uminic acid. With a hot con- 
centrated solution, the salt is precipitated immediately on passing throu|?h the fiher ; 
and each crystal, at the moment of its formation, reflects the light with great vividne^w^, 
exhibiting all the tints of the spectrum. — CutninaU of cafcium forma small needles 
moderately soluble in v,'nt'i^T,-—Ctiminaie of copper is light bluo and insolubk in wattr. 
— Ouminate of had. White precipitate, ineoluble in water, 

Cwm'naU of silwr, C'H'^AgO^, isobtAinod by adding nitrate of silver to cuminate of 
ammoniuio* It is white, curdy, and blackens, nvpidly when exposed to the light. 
When calcined, it leaves a residue of ciirburet of sitTer, CAg*, of a dull yellow colour. 
By dry distillation, it yields carbonic anhydride, cnminic acid, and cumene, 

Dtrivativcs of Cuminie Acid, 

iritroommliilo Aeld. C'*H^*(^<^-)0^ (Gerbardt and Cahour^ Ann. Ch. 
Pbys. [3] i, 73 ; Cahours, ibid, xxv. 36.)^ Produced by the action of filming nitric 
acid on cuminie acid. On boiling the mixture, and then adding water, the nitrtx-u- 
mlnic acid separates as a heavy yellovv oil, which soon solidifies. It ia triturated, 
washed with distilled water, and ervetaUised from alcohol, 

Nitrocuminic acid forms yellowisn- white scales, insoluble in water, easily soluble in 
alcohol and ether. It dissolves in ammonia, potaijh, and soda, forming cjystallisable 
aalt*. The calcium-salt, C"H'*Ca(NO-)0, crystallises in stellate groups of yellow 
nenlles, which become darker when exposed to light. The silvvr^scdt^ C**H'*{NO*)AgC)\ 
is a white precipitate inselublc in water. 

Blnltraonmlnle Acid, C^*H">(NO^)«0*. (Ca hours, Ann.Ch.Ph^. [3] xxt. 37.) 
— Wticn cuminie acid is addwl by small |iortioii8 to a gently heated mixture of fUmiiig 
nitric and sulphuric acid, it diwippeiira without evolution of gas. On boiling the liqtiid. 



CUMINIC ACID. 179 

nd Taponn are erolred, and nitrocuminic acid is deposited in shining yellow scales, 
which may be recrystallued from boiling alcohol. It dissolTes also readily in ether. 
It is not acted npon by fuming nitric acid, even after long boiling. It does not dissolre 
in eanstte ammoniai potash, or soda, or appear to combine with them by long boiling. 
Hydrogen in the nascent state (from acetic acid and iron) conyerts it into diozy- 
cominamic acid (p. 180). 

According to Cahours, dinitrocuminic acid does not combine with bases, and is 
insoluble in aqueous potash, soda, or ammonia, even at the boiling heat ; according to 
Kraut, on the other hand (Chem. Contr. 1869, p. 85), it unites with bases, forming 
yellowish-red salts which become darker on exposure to light. The barium-salt 
C*H»Ba(NO*)*0*, is obtained by dissolving the acid in baryta water, precipitating the 
excess of baryta with carbonic add, then boiling, filtering, and evaporating : it separates 
in films which become crystalline on standing. The calcium-salt, C"H»Ca(N02)K)*, 
prepared in like manner, forms yellow-red needles, which dissolve easily and with 
deep wine-red colour in boiling water. The silver-salt, C"H*Ag(NO')*0' + aq., obtained 
b^ precipitating the calcium-salt with nitrate of silver, and reciystallising the preci- 

Eitate from bouing water, forms light yellow needles, which are scarcely altered by 
ght, but when heated to 100° C. give oflf 5 per cent (« 1 at) water. (Kraut) 
OsTWBlBlo Aeld. C**H>H)'. rCahours, Ann. Ch. Phys. [3] liii. 338.)— This 
acid, regarded by Kolbe as C**£[*\HO)0*, tliat is, as derived from cuminic acid by 
the substitution of HO for 1 at hydrogen, is produced by the action of nitric oxide or 
nitrous add on oxycuminamic add dissolved in a moderate excess of nitric acid : 
C"H»*NO«+ HNO« « C"H"0* + N« + H»0. 

Oxfctuniiuuiile Oxycarainlc 

add. Mid. 

It separatee in small brownish prisms, sparingly soluble in cold water, more soluble 
in boiling water, still more in alcohol. It unites with bases, and some of its salts 
crystallise welL The silTer-salt has the composition C'*H"AgO'. 



\ Mid, C"H"NO» « N.H».(C"H'»0)'' .H.O, or Amidocuminic acid, 
C'»H"(NH^O', also called Cuminamie acid. — This acid, the homologue of oxybenzamic 
add, was discovered by Cahours (Ann. Ch. Phvs. [3] liiL 822.) It is produced by 
the reduction of nitrocuminic add, either with sulphvdric acid, or with ferrous acetate. 

Preparation. — 1. Nitrocuminate of ammonia is reduced by excess of sulphydric acid ; 
the liquid is evapoiated at a gentle heat till all the ammonia is expelled and the 
excess of sulphur is separated ; the concentrated solution is precipitated by a slight 
ezeeas of acetic add ; and the resulting predpitate is collected, washed, dried, and 
reoystaUised from alcohol (Gahoum). — 2. It is also obtained by treating nitro- 
cuminic add with iron filings and acetic add (a brisk action then taking pUce, at- 
tended with rise of temperature, after which the mixture must bo heated for a while 
in the water-bath), digesting the mixture with aqueous carbonate of sodium, filtering, 
neutralising the excess of soda with acetic add, precipitating with acetate of lead, and 
decomposing the predpitate with sulphydric acid. (Bo u 11 e t, Compt. rend xliii. 399.) 

The add forms colourless or light-yellow cr>'stals, sparingly soluble in cold, more 
soluble in hot water; also in alcohol and in ether, 

Jkcompoaitions, — 1. In solution in nitric acid, it is converted by nitric oxide gas 
into oxycuminic add. — 2. By treating aleoholic oxycuminamic acid with nitrous acid, 
light yellow needles are obtained, consisting of a new dibasic acid - C^'N'H'H)* 
(P. Oriess, Compt rend. xlix. 80) : 

2C'«H»«N0« + HNO« « C»H"NK)* + 2H«0. 

This add, icttarded by Oriess as diazocumin-amidocuminic acid, » C'*H'*NK)'. 
0*H"(NH*)0', forms yellow crystals, insoluble in water, and nearly insoluble in alcohol 
and ether. — 3. Oxycuminamic add distilled with caustic baryta or lumps of potash, 
yieldsi an alkaline carbonate together with cumenylamine. 

CombinaHons, — Oxycuminamic add unites with bases, but its metallic salts have 
not been examined. The ethyl-compound, C'»H"(C«H*)NO», is obtained by re- 
dodng nittocumioate of ethjrl with sulphide of ammonium, or with iron filings and 
acetic add. It is a heavy oil, which dissolves in hydrochloric, nitric, and sulphuric 
add, fbnning arrstallisable compounds. Ammonia decomposes it slowly, forming a 
snbstance pfobaUy analogous to phenyl-urea. 

OxyenmLiamic add likewise unites with other adds, forming crystalline salts. 

Hydrochioraie, 0*^**NO'.HCL — Oxycuminamic add dissolves slightly in boiUng 
hydracUorie acid, and the solution on cooling deposits thin needles. The compound 
n^ also be pcep*'^ bj adding alcohol to a mixture of oxycuminamic acid and 
hjrdioefalaric acid, wbereby a eonsiderable quantity of oxycuminamic add is dissolved. 

If 2 



180 



CUMINIC ANHTDKIDE. 



und erapoTOting. Delicate shining prifluis, which dissolve in water, and are parti j 
prbcipitttted on addition of hydrochloric acid. 

The cMoroplatinatt, C'*fl"N0'.HCl.Pt01', ifl obtained by adding alcoKol to the 
mixed solattODs of concentmted dkhloride of platinum and hydrot^hlorato of oxycami* 
namic acid» wacming tho mixture till it dissolves, then filtering and leaving the 
solution to evaporate. It forms long reddish needles* 

The nitrate forms beautiinl prisma. 

Sulphatf, 2C^*H*'N0*.iPS0*.— Oxjcuminamic add i^ mixed in alight exoeaa with 
oil of Titriol diiut4[^d with an equal bulk of water, and the mixture ia diasolved in warm 
alcohol On cooling, thin^ white, silky needles are deposited* The compound has a 
elightly sweet taBte, dioaolTei sparingly in cold, easily in hot wat«r. 



Sloxyctimlnamio acW, C'*n'^N=0' = KlH*.(C''H'Or,n.O, or Biamidoeuminie 
a&id^ C^"IP"(NH')'.0': alHt^ called Bieumin&mic odd. — ^This acid, tho homologue of 
dioxybenzamic acid» ia obtained by reducing dinitroeuminic acid with iron filings and 
acctie acid, the mode of preparation being simOar to that of o^cnminamic add. It i« 
crystalliaable, and unites with bases (BouUet, Compt. rend, xliii 399). The first of 
the above mtional formulae repreaenta the comp:)und as a diamic acid derived from a 
hypothetical dioiybenzoic add, C**H'*0*, containijig the tTifltoraic radicle C**fl.'0. 
CUBCXBTZG AZiCOHOIi. Syn. with Cymylic Axcoeol {q. v.) 
CimiXliZC fLXiDBHTBE. ^yn. with HTDaiDB of Cumtl (p* 182). 

OU MXJi XC AWSniKXXlS. Anhydrous Cuminic acid. CuminaUf of Cttm^l^ 
Cwfl^O' = (C"^lt"OfO.— [Gtrhardt (1852), Ann. Ch, Phya. [3] xxxTiL 304.]-— 
Produced by the action of chloride of cumyl on cuminate of e<4ium* The two 
aubstanecfl, perfectly dry, are heated together iu ti fla.sk, till the odour of chloride of 
cumyl completely diaappi'ara. A syrupy muss ia then letl, which, when treated with 
hot. water, yields the anhydride. Tha product may bti purified by recryatalliaing 
it several time** from pure ether. 

Cutninic unbydride^ recently prepared, is oily, tasteless, nearly colourless^ and 
inodoroua, but soon experiences a molecular change, by which it ia converted into a 
mass of Tery brilliant rhomloidal cryatala. In moist air, it is rapidly converted into 
cuminic ucid. With ammonia it fonns cununamide. 

Cumin acsticAnhtdriiib. See Acbto-cuhinic Aitbtdbibb, (i. 2L) 

OuMiKO-BENZoi0 Akhtdbidb. See Bskzok^vminio AifHTDaiDiL (i. £S8.) 

CtTKiiro- BIT OB 24^10 ANHTDBinH. Cumifiate of Enffcnyt, C*H^O* ^ C**H'^0, 
C*'H*'0.0. — Isomeric with cuminic ombydride; obtained by heating eugenic add with 
chloride of cumyl CrystaUisee in colourless, very brilliant plates, which melt very easily, 
but do not Tolatiliae below 400° C. It is not decomposed by boiling potash-ley, but when 
fused with hydrate of potassium, it i^ resolved into cuminate and eiageiiat4? of potasriuDa. 
Sulphnric add decomposes it in a simihir manner. Fuming nitric acid decomposes it 
readily, proilueing a reddish -yeDow tenacioua mass, in which crystals may be obserped. 
Hydrochloric add does not act upon it, oven at boiling heat, (Cahonrs, Ann. Ch. 
Phys, [3]xli.491.) 

CuMifT-CBKAJTT HYLIC Anhtdkide. Cuminate df (Enantht/J ^ C^'H^'O'^CH^'O. 
C*H"0.0.^ — Produced by the action of chloride of cnmyl on oenanthylate of potassium. 
It ia an oily liquid, heavlcT than water, and smeUing like apples. Its vapour exdtee 
coughing. (Chiozaa and Malerba, Gerh. Trait^ iii. 601), 

Cciio*sAi.icTLous A K B YU B I D B, CuTTiinate of Salieyl, Ctemosalict/i, C"H"0* — 
Ci*H»«O.C^H»0%0. (CahoTirs, Ann. Ch. Phys. [i] Hi. 19 7:)— Obtained by beating 
Balicylous acid with eloride of cnniyL Crvstalbses in eolourless, shining, friable 
* prisms, which melt to a dear oil at a gentle heat, and solidify on cooling. Insoluble 
in cold water* f?lightly soluble in boiling water ; soluble in alcohol, espedul ly when 
warm ; insoluble iu ether. With chlorine, brotnirif^ and fuming niirte acid^ it yields 
crystjilbaable pmKiucta It is not attached by solid cans tic ^/ojA or by aqueous potash, 
even at iha Ixtiling heat. 

CuMO'METHYL-sALiOTiic AwHTiiBinB. CktmtnaU of MtthyUAitlicyl, C'»H*"0* — 
C"H"0,C'H*(CII*)0*.0. (Gerbardt, Tmit^, iii, 317.)— Produced by heating chloride 
of cumyl with salieybte of methyl (oil of wintergreen). The product is a viscid oil 
which rf^mains fiuid for a long time, but if a email quantity of ether is poured into it, 
it solidities in a radiated mass as the ether evapomtes. It crystallises from boiling 
alcohol in very brilliant rhouibic scales, insoluble in cold water, sjiariiigly soluble in 
cold aleobnb very soluble in ether, which, as it evaporates, deposits the compound in 
rhomboidol priHrna, often of eonsideraljlo sixe. From a hot saturated alcoholic solution, 
it is deposited as an oil which remains liquid for a considerable time. 



i 



CUMINIC ETHERS — CUMONITRILE. 181 



CUMiaiC w r mmM B. Cuminate of Ethyl, C'^H^^O' « C><*H"O^C''IP. — 
Obtained by passiog hydrochloric acid gas into a solution of cuminic acid iu absolute 
alcohol, till it is no longer absorbed, then heating the liquid over tiie water-bath to expel 
the excess of alcohol, distilling the residue over the naked fire, washing the distillate 
with carbonate of sodium, and rectifying over massicot. It is a colourless liquid, lighter 
than water, and having an agreeable odour of apples. It boilc at 240^ C, giving off* a 
raponr which easily ukea fire and bums with a bluish flame. Index of refraction of 
the liquid, 1*604. Vapour-density, 6-65. When heated with solution of potash, it 
yields alcohol and cuminate of potassium. 

Cuminate of Phenyl. C"H'»0« = C"H>'O.C«H».0. (Williamson and 
Scragham, Proc Roy. Soc. viL 18. — Kraut, Dissertation uber Cuminol und Cymen, 
1864.) — Produced: 1. By the action of chloride of cumyl on phenate of potassium 
(W. and. Scr.). — 2. By the dry distillation of cumo-salicylic acid, or of a mixture of 
equivBlent quantities of chloride of cumyl and salicylate of sodium (Kraut). Crystal- 
lites in long white needles, melting between 57^ and 68^ C. and distilling without 
decomposition. It has an agreeable odour, resembling that of benzoate of phenyl, 
especially when heated. Insoluble in water^ easily soluble in alcohol and ether. 

A mixture of this ether with nitrate of sodium^ heated with strong sulphuric acid, 
yields dinitroeuminic (and probably also nitrocuminic) acid. By sulphuric acid alone, 
it is resolved into cuminic and sulphophenylic acids. It is decomposed by alcoholic 
(not by aqueous) potash^ yielding cuminate and phenate of potassium. (Kraut.) 

WOJam Syn. of Htdridb of Cuictl (p. 183). 

ACZB. Glycocol-cuminic acid, Cumyl-oxyaceiamic acid, C^^H'^NO' 



— N.H.C"H"0.(C«H«0)".H.0.—Thi8 add, homologous with hippuric (benzoyl-oxy- 
acetamic) acid, is produced by the action of the silver-compound of glycocol (oxy- 
acetamate of silver) on chloride of cumyl : 



Nja«.C«H'O.Ag.O + C»«H»0.a - AgCl + N.H.C>»H»'O.C2H«O.H.O. 

The cnminuric acid is extracted from the product by warm alcohol, and remains on 
evaporation as a brown mass, which may be purified by pressure and recrystallisation. 
Its silver-salt is C"H^*AgNO'. The acid heated with aqueous hydrochloric acid is 
resolved into glycocol and cuminic add. (C a hours, Ann. Ch. Phys. [3] liii. 366.) 

CUlUJITXk C'*H". A monatomic radide, of which cuminol, C'^H'H), may be 
reeled as the hydrate » C>"H".H.O. 

IfM M — ■■»«^^M ■■■■■I- See Hornblende. 

CVlKa-a^TOOXh Syn. with Hydrate of Cumtlbne (hyp.) « C'»H'*.H«.0«. 
(See page 184.) 

CVMOXh Syn. of Cumene (p. 173). 

CVlKOWXTBZXdB. C'»NH", or Cyanf<f<f 0/ Cwmrny/, C»H".CN. (Fr. Field. 
Ann Ch. Pharm. Ixv. 61 ; Mem. Chem. Soc iii. 408.) 

Formation, — 1. By the dry distillation of cuminate of ammonium, cuminamide being 
formed at the same time. ~ 2. By the action of bromide of cyanogen on cuminate of 
potaasiam, carbonic anhydride being likewise evolved (C ah ours, Ann. Ch. Phys. 
[3] Iii 201): 

C>»ir»KO« + CNBr = C0« + KBr + C'^NH". 

— 3. By the action of heat on cumosulphophenamide and on cumosulphophenargenta- 
mide. (Gerhardt and Chiozza, Ann. Ch. Phys. [3] xlri. 167.) 

Prfparaiion. — Cuminate of ammonium is heated in a retort to complete fusion, and 
then maintained in violent ebullition, whereupon large drops of cumonitrile pass over 
together with water. As soon as the oil has completely passed over, it is separated 
with a pipette from the distillate, and the w^atery liqmd is poured back into the cooled 
retort, and redistilled five or six times. The whole of the oil thus obtained is freed 
hj washing with ammonia from traces of dissolved cuminic acid ; it is then washed 
BQceeesiTely with hydrochloric add and water, dried by leaving it for some days over 
chloride ox caldum, and rectified. The portion which goes over last may contain 
water. 

Properties, — Transparent, colourless oil, of specific gravity 0*766 at 14° C. Refracts 
light strongly. Boils constantly from platinum wire at 239° C, under pressure of 
07686 metv Has a very strons but agreeable odour, and a burning taste. It dis- 
solves bat slightly ia watery and renders it milky. Alcohol and ether dissolve it in all 
proportiona. 



182 CUMOPHENAMIDE ^ CUM YL, HYDRIDE OF. 



Dfcowposituins,— 1. The vapour of cuinoDitrile is inflaminable, atid hitms witli a 
brilliiiat flame. —2. CumoiiitriJe is but diglitly al tinned by istrong n/^nV (u:kl in tlie 
cold, but oil iHuliog, euminjc or nitroeuminic ncid is pmduced. — 3. Ileatod with 
potasJiium, it bcuoint'ft darker and forma a kirper quantity of cyrtiddo of potassium. — 
4. Alcoholic wj^ajf A does not alter it immtHliutely, but oonverta it^ aftor a few di^y^ 
into a ciysl^fline pulp, cjousisting of the oil turned yellow and cutniuiLoiidc. 

ClTMaFHSirAllSXllS. SiH? CuiDXA^nsB (p. 177). 
CITMOBiLXtlCTX. Syn. with Cumosat-icylous AjrarDRiDB (p. 180), 

CiriilOSikmrcrSb&BSIBfi. [ See C^rMENjUcms {p. 177). 

CITMO^TXi. Syu. with CunTi^ 

GirM01fX« Weltsien'a nara^ for the radicle C'^H", of which cuminol (md. infj) 
mny be regarde=d as the hydrate, 

CtmCT^. Cumoxffl, CH^'O. — An acid organic radicle homologous with benzoyl, 
and forming a seriea of compounds correspoinling to the benzoyl- compounds, xvL 
ht/dnds of cumyl or cuminoi^ C'"M*'O.H ; M^dratc of cnmt/l, or atminic acidj C'H'^O, 
H»0 ; nitride of cumyl and hifdrtigen^ or cuminamide^ N.B.^C'"'H"0, &c. 

Cumyl in the fret state^ or Cumuli de of Cum^l, C'*H"0', is obtained by tho 
action of chloride of cuiuyl on an equi Talent quantity of comylide of potasslaffl : 

C'«H"0.C1 + C'*H"0,E = KO + (C'"H"0)*. 

The mixtnpfi is gently heated to fiicilitate the separation of the chloride of potassium, 
and the resulting mass is treated with a weak solution of potash to decsompoae the 
last traces of chloride of cumyl It in then digested with ether to dusolre out the 
cumyl, and the ethereal soktion is left to eTaporate, 

Cumyl is an oily liquid^ heavier than water ; ita odour is scarcely perceptible at 
ordinary t-emperatures, but becomes very stn^ng under the influence of heat, and 
resembles that of the geranium. It boik at 300^ C,» decomposing at the nune time, 
and yielding cuminic aeid, aerend substances less highly oxidi«ed than that acid» and 
earlxjnaceous matter. It is combustible, and bums with a smoky flama Heated with 
potiishj it is converted into cuminic acid and hydride of cumyl: 

2C"H"0 + KHO =^ C'*H»O.KLO 4- Ct»H^iO.H, 

Cumyl dissolves sparingly in cold alcohol, but boiling alcohol dissolres it in e<m- 
siderable quantity. (Chiozza, Ann. Cb. Phys. [3] xjomL 246.) 

CUMY1# , STUBOIB OF. Cuminic AldAydr, Cuminol. C'H^^-C^'H'^O.H. 
(Oerhardt iind Caboure, Ann, Ch. Phys. [3] i. 60.— Bertagnini Ann. Cb. 
Pharm. Ixxjtvi. 276. — Kraut» Bissertali&n iibtr Cuminot und Cymen, 1854; Ann. 
Ch. Pharm. icviii. 365. — G nu jliw 148.)^Thi8 compound exists in the essential oil of 
ctimin, which is in fact a mixture of cniminol with a hydrocarbon named Cpmmt 
(C'li'*). On distilling this essence, the cymcne pasaes over iirnt at about 200'' C, and 
afterwards the hyflride of cumyl. To obtain this latter in the pure state, it should be 
distilleifi aa rapidly as possible in an atmosp>here of carbonic anhydride. Auotlier modeof 
se[varntion is to a^tate the cumin-oil with a moderately eoncentrated solution of acid 
sulphite of potassium or sodium, which takes ii|> the hytlride of cumyl, but not the 
cymene, forming a cry stall iJie oomponnd from which the hydride of cumyl may be separ- 
ated by potash. Hydride of cnmyi also occurs, together with ciTncne, in the Tol&tileoil 
ot^tained from the seeds of the water-hemlock {Cicttia vtrosa), and may be.Bepttrated 
by acid sulphite of potasj«ium as above* (Trapp, Ann. Ch. Pharm. cviii. 38iS.) 

Propertirs. — Hydride of cumyl is a colourless or slightlj' yellow liquid, having a 
strong and persistent odour of cumin, and an amd burning tjiste. Boiling point 220'^ C, 
(Gerhardt and Cahours); from platinum at 220*4*^, or, correcting for the mcn^urial 
column in the thermometer, at 236*6^ (Kopp). SpedjRc gravity in the liquid state 
= 0-9727 at 13*4° C. = 0'9832at 0" (Kopp.) A^apour-deasity = 6-24 (obs.) = 6*13 
(cale. 2 vols.). Composition, by analysis (mean), 80 '8 9 per cent, carbon, 84 6 hydrogen, 
and 1066 oxygen, the formula requiring 81-08 C, 811 H, iiud 10 81 0. It is isomeric 
with the OBseotial oils of anise, fennel, star-anise, and tarragon. 

IkcompotUiofUt, — 1. Hydride of cumyl may bo diiitilletl without alteration in close 
vessels, out when Imiled for some time in contact with the air, it is converted into 
ciaminic acid, tep^othcr with a resinous substance. The same transformation takes 
place even at ordinary temperatures, especiidly m contact with water, or more quidvly 
III contact with a base. — 2. Byfuminff nitric add in the cold, cuminol is converteti into 
cuminic acid ; heated flath niti'ic add, either strong or weak, it yields nitro- cuminic 



I 




CUMTL, CnLORn)E OF. 183 

ftcid, together with resmoiu prodacts. — 3. By a mixture of acid chromate of potassium 
and suiphurie acul^ it is oonTertod into cuminic acid (Gerhardt and Cahoars); by 
pfdlonged action into insolinic acid (H of m an n, Ann. Ch. Pharm. xcvii. 207). — 4. With 
chlorine or bromine it forms substitution-products in which 1 at hydrogen is replaced 
by chlorine or bromine ; but with pcntachioride of phosphorus, it forms the compound 
C'*H'*C1*, deriyed from hydride of cumyl by the substitution of chlorine for oxygon. 
— 6. Dry ammonia gas converts cuminol after some time into a substance resembling 
hydrobenzamide (Gerhardt and Cahours). Sie veking (Ann. Ch. Pharm. cvi. 367) 
could not obtain thia body. — 6. Sulphide of ammonium decomposes cuminol, forming 
thiociiminol, C"H"S, in which the oxygen of hydride of cumyl is replaced by sulphur. 
— 7. Heated with potassium^ it gives off hydrogen and forms cumylide of potassium, 
C**ff K).K. — 8. Cuminol boiled with aqueous, or more quickly with alcoholic potash^ is 
conrerted into cmninate of potassium and cymylic alcohol : 

2C'^»«0 + KHO = C'»H"KO« + C'«H"0. 

— 9. Caminol heated with solid caustic potash, yields rarious products, according to 
the degree of heat applied and the manner in which the two substances are brought in 
contacts When the solid p otaah is covered with cuminol and sb'ghtly heated, cumylide 
of potaasiiim is formed. When cuminol is added by drops to melting potash, the mass 
first tarns red, then quickly white, and forms cuminate of potassium, with elimination 
of hydrogen ! 

C»»H»«0 + KHO = C»^H"KO« + H«. 

It however, the heat applied is comparatively low, cuminic acid and cymene are formed, 
without evolution of hydrogen : 

3C"H'«0 + KK) = 2C"ff 'K0« + C'»H'*. 

In thia case it may be supposed, that the cuminol is first resolved into cuminic acid 
and cymylic aleohol, and the latter subsequently into cuminic acid and c^inene 
t Kraut). — 10. With chloride of cumyl, cuminol yields hydrochloric acid and cumyl 
(p. 182). 

Combinations. — Hydride of cumyl unites with the acid sulphites of the alkali-metals, 
forming crystalline compounds. The ammonium-sat t crystallises in needles ; the potas- 
sium-salt in scales ; the sodium-salt, C'®H'*O.NaHSO', in colourless inodorous needles, 
which become yellow by keeping. 

Derivatives of Hydride of Cumyl. 

ComjUda of >ot«— tnnii C^*H"O.K. — Produced by heating hydride of cumyl 
with potassium out of contact of air ; also by heating solid hydrate of potassium in the 
midat of hydride of cumyl : in the latter case, water is eliminated and the potash is 
converted into a gelatinous mass. To obtain pure cumylide of potassium, the product 
formed by the first process is pressed between filtering paper, and placed in vacuo 
over sulphuric acid, which absorbs the undecomposed hydride of cumyl. 

Cumylide of potassium is an amorphous gelatinous mass, quickly converted into 
ruminate by contact with the air. Water decomposes it into hydride of cumyl and 
hydrate of potassium. Heated with chloride of cumvl, it yields chloride of potassium 
and free cumyL With chloride of benzoyl, it yields an oil resembling cumyl, pro- 
bably benzo-cumyl, C'H*O.C'«H"0. (Gerhardt and Chiozza, loc. cit,) 

dOoroeaznliiolf C'*H"C10. — Produced by passing dry chlorine through dry 
hydride of cumyL It is a yellowish oil, heavier than water and having a very power- 
fril odour. By exposure to moist air, it is converted into hydrochlonc and cuminic 
acids: 

2C»H»C10 + HK) = C"H'K) + C«»H»K)«. 

It is decomposed by dry distillation, yielding hydrochloric acid and a peculiar oil, and 
If^ving a residue of charooaL Strong sulphuric acid dissolves it, forming a crimson 
N>lution and giving off hydrochloric acid. The liquid exposed to moist air, quickly 
yields crystals of cuminic add. Chlorocuminol when recently prepared, is scarcely 
attacked by ammonia, differing in that respect from the isomeric compound, chloride of 
rumyl, which is immediately transformed by ammonia into cuminamide. (Gerhardt 
and Chiozza, Ann. Ch. Phys. [3] i. 82.) 

aromocnininoly G'*H"BrO, is a heavy oil resembling chlorocuminol, and obtained 
by the action of bromine on hydride of cumyl. (Gerhardt and Chiozza.) 

CUICT&* <IM&aBZ»B OV. C>*H"O.CL— Obtained by the action of pentachloride 
of phosphorus on cuminic acid. It is a colourless rezy mobile liquid, of specific gravity 



184 



CUMYLAMIDE^ CUPR AMINES. 



I -070 «it 15^ 0. Boils between 256^ and 268** C. By eipoauro to moiat &ir» or moi* 
rupidly by Iwiting with caustic potash, it is conTertal into hydrochloric aivd emniuic 
aeid9. It is Bti^nglj heatodby contact witb atrong alcohol^ yiddiiig hydrochloric ucid 
and ciirain-iito of ethyl 

With dry amm&nia g&n, or with carbonafe of amnwnium^ it forms cwm in amide j with 
phenylatnim it yieldg pheuykundiiamide or cumanilide. (C a hour a, Ann. Ck Phys. 
[3J Jtriil 3470 

CVmXAJms^B. Sya with CuimiAMiDE (p. 177). 

CirMTXiEBlXL C^"!!*'.— A hypothetical diatomic rAdicIe, bomologoufl with bcii:^- 
Icne (i. 577), of which the following compounds are koown. 

Chloridb of Cuktlbnb, Cklorocumolt CAlorocuminoi, C'®H*'C1'* (Ca hours. 
Ann. Ch. Phya. [3] ixiii. 346.— Sievekiiig, Ann. Ch.PIumn. cvL 268* — Tiittucheff, 
J. pr. Chcm, Ixxr. 370.) — Produced by the action of pentachlorido of phoaphonia 
on hydride of cumyl : 

c»»H**o 4- pa* = pci»o + c'*H'«a». 

It is a limpid oily liquid hariugi a penetrating but not unpIeosaBt odour^ hearier than 
water and insoluble there>in [ easily soluble in alcohol aud ethen Boils betweeD 25o° 
and 260*^ C. (Ca hours); at 255° with alight decomposition. (Tiittscbeff.) 

I)ecomp(mtion». — 1. Heated w^tli alcoholic ammonia in a seuJcd tube, it forma 
chloride of ammonium and u thick yellow oil (Sievoking).— 2. It does not appear 
to be decompoeed by aqueous po/(«A (C a hours)* — 3. With mdphydraUt of ptjtassium 
it yields chloride of potassium, and a viscid product of repulsiTO odour (C ah ours). 
By prolonged treatment of the alcoholic solution witb 9ulphid« of ammonium^ it 
forms a dark-red resin soluble in other (Si ct eking). — 4. Freshly precipitated 
oxide of nlrvr cctnverta it into cumino! (TiittscheH'). — 6. When 2 at. rthyfatf of 
Modium are heated with 1 at. chloride of cumylene^ chloride of sodium and a red liquid 
ore obtained. When thia product is distilled, ^t alcohol, and then, between 170<^ 
and 2S8° 0., an oil paaaea over, which behares with acid sulphites of alkali-metals 
like cuminol (Sieveking).— 6. With acetate of ailver, it forms aci'tate of cumytene 
(SieTeking), with bensoaie of »ilvtT, bonzoate of cumylene. (Tiittscheff.) 

Ac BT 4T B o r Cu M YtBXB. Acctatc of Cumogl^col^ Biaaiate of Cumol, C"H'*0* *» 
(C^II^U)^ (C'*H»')''.0\ (Sieve king, tot\ cii.)— Chloride of cumylene is miied with 
excess of acetate of silreTi and the reaction, wluehimjnedi&telY ensues, id Hually aided 
by a gentle heat. The piroduct is treated with etlier; the solution eTaporated; and 
the residue is washed with aqueous carbonate of soda, and cryBtallisea ^^om ether, 
whereby yellowish cryatalB, contamiuated with an oil, are obtuined. When pore it 
forms colourless crystals; resembling the swallow-tail crystals of gypsum. It melts at 
a moderate heat., and dififuses a powerful odour of acetic acid and cominoL 

BHKEOATBOFCnMTTLBWB. BtnxooU of Qtim offiyeoi. Bibentmk of Cumol. C* H^O * 
=- tC'H*0)*. (C'»H")".0«. (Tiittscheff, ^. ci/.>-^en pta. chJorocumol are mixed 
in a porcelain dish with 1 6 T^ts. benaoate of sUTer ; the mass thereby formed is treated 
with ether, which leares chloride of silver; and the resulting solution of benaoate of 
cumoglycol is left to evaporate spontaneously, whereupon a brownish yellow oil, 
solidifying in crystals in a few days, is deposited. This is pressed between paper, 
washed with aqueous ammonia, ana recrystaliiHod alternately from etlier>alcohol ajid 
absolute alcohoL 

It forms brilliant^ colourtesa needles, melting at 88° C, and solidifying in crystals 
on cooling; soluble in tdcoholf especisdly in warm strong alcohol, and precipitated by 
water ; soluble in tthtr^ acctont^ and chioroform. 

It cannot bo volatilised without undergoing decomposition. It is dissolved by cold 
sulphuric acid with dark red colour ; the solution blackens by boiling ; it is not 
Attacked by boiling ntiric acid; it is not affected hy ammonia or by ooncentratt-d 
bitrtfta-watcr ; distuled with caustto potash, it yields benzoate of potassium and 
curninol. 

CUBSYXklO ACID. Syn. with Cricixic Acm. 

ctriv[irz.-sAx.icir2.ii.»ixis. 

CITPSlf. A shallow cup-shaped vessel made of bone-earth rummed into a mould 
which giifcs it its shape. It is used in assaying gold and silver with lead. (i5ee Gold 
and S11.TKK.) 

CtrpmAUCnrsa, CUF&AMllCOirZAS, ClTFXAKlllOM'nrjItS. Bases de« 
rived from the types KH" and NH* by substitution of one or more atoms of copper for 
an equivalent qTwuitity of hydrogen (p. 70)» 



I See C?imiNJkiQj)B (p. 178). 



J 



CUPROUS MANGANESE — CURARINE. 185 

See LiNAsiTE. 

A Tarietj of wad or earthy manganese. (See 
MAiroAjnsB, oxidbs of, and Wad.) 

CUVRZC COMPOnWBS. See Coppeb (pp. 41, 55). 

Cu » 31*6. The radicle of the cupric compoundB (p. 41). 
Katiye cuprous oxide (p. 70). 

mMTTMrn A sulphide of copper and lead from Chili, occurring in 
forms of the regular system, with cubic cleavage ; also massive, granular. SpMific 
gravity — 6*408 to 6*423. Hardness =» 2*5. Lustre metallic. Colour blackish lead- 
grey. Streak black. Bather sec tile and brittle. Fuses readily on charcoal before 
the blowpipe ; yields with soda a cupreous lead-globule ; melts and gives off sul- 
phurous anhydride when heated in an open tube. 

According to Plattner's analysis (Fogg. Ann. Ixi. 672), it contains 64*9 per cent, 
lead, 19-5 copper, 0*5 silver, and 15*1 sulphur (estimated by loss), whence the formula 

2P6A(V5,or^J,|s«. 

According to Q-. Ulrich (Berg. u. hiittenm. Zeitung, xviil. 221), a mineral of the 
same composition is found in small quantity on the M'lvor river in Victoria, Australia. 
It has the aspect of fine-grained galena. Hardness a 3*0 to 4*0, and apparently 
rhombohedral cleavage. 

CirVKOSms. Ccu =* 63*2. — The radicle of the cuprous compounds. (See 
COPPKB, pp. 41, 46.) 

cmLAJULi Urarif Woorara^ Woorali^ Wourali. — A resinous substance used by 
the Indians of South America for poisoning their arrows, and consisting, according to 
several authorities, of the aqueous extract of a climbing plant belonging to the genus 
Strycknos. It is a brown-black, shining, brittle, resinous mass, almost whoUy soluble 
in water, either cold or warm ; sparingly soluble in absolute, easily in aqueous, alcohol ; 
partially soluble in ether. It has a bitter taste, neutral reaction, and when heated, 
bums with a yellowish-red flame, giving off vapours which have a disagreeable odour. 
Its chemical nature is not accurately known. Boussingault and Eoulm attribute its 
poisonous action to the presence of a peculiar alkaloid, curar ine (g. v.), while others 
ascribe its effects to the presence of strychnine. 

Cnrara may be introduced with impunity into the alimentary canal, except in very 
large doses, but if introduced into a puncture in the skin, so that it may mix with the 
blood, its action is rapidly mortal. Humboldt states that the earth-eating Otomaks- 
OD the Orinoco are in the habit of anointing their thumb-nails with it, and that a 
mere scratch with such a nail is sufficient to prodace fatal effects. The Indians use 
arrows poisoned with curara in the chase, the flesh of animals thus killed being per- 
fectly wholesome. Curara acts chiefly on the motor nerves, the functions of wluch it 
completely arrests, while the sensorial nerves retain their activity. Death ensues 
from paralysis of the nerves of the respiratory organs. 

From the researches of Beynoso, it appears that chlorine and bromine decompose 
curara, and completely neutralise its poisonous action. Iodine also acts as an antidote, 
though it does not completely decompose the curara. Nitric acid acts but slightly on 
curara, but may be useful as a caustic in cases of poisoning by that substance. 

Curara has been tried, but without success, as an antidote to str>'chmne. It has 
also been tried as a remedy in cases of traumatic tetanus, and in one instance with 
success ; in other cases, however, it has been found to produce no effect whatever. 
(Handw. d. Chem. iL [3] 271). 

CVmAJUDra. (Houlin and Boussingault, Ann. Ch. Phys. [2] xxxix. 24. — 
A de Humboldt, ibid, xxxix. 30.~Pelletier and P^troz, ibid, xl 213.— On the 
Poisonous Properties of Curarine ; Pelouze and CL Bernard, Compt. rend. xxxL 553. 
— A Reynoso, ibid, xxxix. 67. — E. Pelikan, ibid. xliv. 507. — M. Milleroux, t&M^ 
xlvii. 973.)— An alkaloid existing in curara. 

To prepare it, Pelletier and Petroz treat the alcoholic extract of curara with ether, 
to remove fat and resin ; dissolve the residue in water ; precipitate the foreign matters 
with basic acetate of lead, and remove the excess of lead-salt with sulphuretted hy- 
drogen ; decolorise the liquid with animal charcoal ; evaporate the filtrate and expel 
the acetic acid by adding sulphuric acid diluted with absolute alcohol ; remove the 
alcohol by evaporation ; precipitate the sulphuric acid with hydrate of barium ; remove 
the excess of baryta by means of carbonic acid ; and finally evaporate the filtered liquid 
to dryness. 

Curarine thus prepared is a non-crystalline, yellowish, horny mass, translucent in 
thin fragments, it is deliquescent, and hta a bitter taste. When heated, it chars, 



186 



CURCLTIMIN— CYAMELIDE. 



emits AH odour of burnt liora, and yields ii slight Bublim»te. It dissolr^ iJi all pro- 
portjotts in wntoT and alcohol^ but is insoluble in ether and in oil of turpentine. It 
blnp« litmus piiper r<*ddpned by Acida, and redd^na turmeric paper. 

It united with acid/), fonning bittor miltSv The guiphatA, h^drochloraUt and aeetais, 
which are the only ones yet knowit, are uncrystallifuiDle. 

According t^ FeUkan, curarlae exhibita with acid chromate of potasHum and 9ul- 
phurie add^ with ferrocifamde of potusmum and sulphuric acidf and with ]j&roxid£ of 
Ifad^ the same iea4rtion8 aa Btrjchnine^ excepting that with cumrine they are more 
permanrat. It likewise exbibit§ the same deportment as strychnine when aubjected 
to electrofysii, a red colour apf>earing in both cases at the positive pole. 

The physiological action of curarine appears to be the same tu that of curatm. 
Pelikan found that 005 grma. of curarine introduced under the skin of a rabbit JdUed 
it in a short time. Ho is of opinion that there is no antidote to the poisonous action 
of curara and mrarine. 

CVKCnrBf A. See Tusmnia 



(A, Vopel Behw. J. xviii 212. — Pellctier and Vogei J. 
Phiirm. July 1815, p. 259. — V ogel, Jun.. Ann. Ck PharriL xHt, 297.)— A yellow re- 
sinous snbetance contained in turmeric root* To extract it, the pulTcrised root is firet 
boiled with water to remove gummy matters, &c, ; the residue then treated with boil- 
ing alcohol ; the filtered alcoholic solution evaporated; the residue digested with ether; 
and the ethereal solution evaporated at a gentle lieut. The residue consists of curcu- 
min contaminated with a small quantity of essential oil, &om which it may be fre^ 
hy redissolvinff in alcohol, precipitaldiig with acetate of lead, decomposing the lead* 
precipitate with sulphuretted hjarogeu^ and then treating it with boiling ether, which 
takes up the curcumin. 

By eraporating the ethereal BDlulion» the corcumin ia obtained in thin tvsuiofus plaf«8 
of the colour of cinnamon, but yellow when reduced to powder. When exposed to 
snnahinet it ^dually loses it* colour and becomes yellowish -white. It is heavier than 
water, and msolnblo thert^in* but dissolTes with facility in alcohol, ether, and oiJa 
both fixed and volatile, Tlie alcoholic BolutioD is precipitated by gelatin. Curcumic 
melt« at lO'^C*, and ia completely decomposed by distillation. 

CtrSCOVOTE* Syn, with AarcDCB (l 357), 

CUSTJLSLXir. A non-azotised crystallisable substance, soluble in alcohol, spar- 
ingly snluble in water, contained in the bark of the true angu*tura {Ctitparia fthri^ 
fvffft) (Salad in, J. Cbim. med 1833, ix. 388). Her^og (Arch. Pharm. [2] xciii 
146) waif not able to obtain this substance. 



A peculiar modification of cellulose, contained, according to Fremr, in 
the epidermis nf leaves, petalSt and fruits, together with ordinary cellulose, albumin ^ 
pectons suWtances, and fat. It is especmlly distinguished from ordinary cellulose 
(i, 820) by being insoluble in ammoniacal solution of oxide of copper (cuprammimia) 
To prepare it, the epidermis of leaves, or the leaves tbemaelve*, are boiled for half an 
hour with weak hydrochloric acid and washed with water; the woody fibre ia removed 
finom the remdue by aqueous oupnimmonia ; and the undissolved portion is treated 
ancceaBiTely with water, hydrochloric acid, weak a([uoous potsah, alcoliol, and ether. 
(Fremy.) 

Cutin exhibits under the microscope the aspect of an amorphous perfor»t4?d film. 
It is very extensible, contains 73-66 per cent. C, 11 "37 H, mid 14 97 O, appronching 
in composition to the fats (Fremy). It decom}X>ses when hrnted, profiucing fatty 
acids. It is not decomposed by cold nit He arid, but when boiled with that acii yields 
all the products that are formed in like manner from the fata, especially suberic acid. 
It is not altered by contact with cold oil of ntriol or tioiling hydrochloric add. It is 
saponified by boiling concentrated aqueous potash, and from the soap thus formed, a 
liquid fatty ncid may be separated, which is soluble in alcohol and ether, but appe«ft 
to be different from oleic aciiL Cutin is not altered by dilute aqueous dkJit^ by 
amflumt^, or by any neutral solvent, (Fremy, Compt. rend* xlviii. 6d9.) 

According t-o Pay en, on the other hand (Compt. rend. iJviii. 893), the epidermis of 
plants consists of cellulose imprt»gnatcd with it\i», nitrogenous bodies, and inorgxnJe 
salts ; he denies the existeuc<e of any peculiar constituent of it not containing nitrogen 
or cellulose, and reigards the cutin of Fremy as a product of the transformation of eel* 
Iidose by the reagents above mentioned. 

crrJkllCBI»Z]>8. tmoluftk Ct/anvrie acid, wCNHO. (Liebig, Pogg, Ann. xv. 



661 J XX, 384). A white crystalline substance polymeric wiJh cyanic acid (perhaps 
C'N-II^"l, which is produced, together with liquid' cyanic acid, in the dry distillation 
of cyanuric acid ; sometimes fonns sjiontaneously in the agtieous solution of cyanic 
add; and is obtained when certain cyanates are treated witn concentrated adds; for 



CYAMELURIC ACID. 187 

nple, when cyanate of potassium is triturated with fuming nitric or sulphuric add, 
with ciystallised oxalic or tartaric acid, or with strong acetic or hydrochloric acid. 

Cjamelide is tasteless, inodorous, insoluble in water both hot and cold, also in al- 
cohol, ether, and dilute adds. When heated, it is converted into cyanic acid, which 
ToUtilises. Heated with strong sulphuric add, it decomposes with effervescence, 
yielding carbonic anhydride and sulphate of ammonium. It is not altered by boiling 
with hydrochloric or nitric add. It dissolves easily in potash, and the solution when 
evaporated yields cyanurate of potassium, a small quantity of ammonia being, how- 
ever given ofl^ arising from a secondary decomposition. Cyamelide is likewise 
soluble in ammonia. 

CTAanOiintlO ACZB. C«NaT«0*. An add discovered in 1860 by Henne- 
berg (Ann. Ch. Pharm. Ixxxiii. 236), who assigned to it the formula, OH*N'0*. 
Oerhardt (Compt chim. 1860, 104) regarded it as C«H*N*0*; but Liebig (Ann. 
Ch. Pharm. xcv. 281) showed that the true formula is OH*N'0*. The add is tri- 
baaic and may be derived from the type, NH'.SHHO, according to which its rational 

formula is ^ H*(o*" 

Cyamelnric add is formed from mellone by the action of alkalis at the boiling 
heat, the reaction being represented, according to Liebig, by the equation : 

2C»N'«K« + 9HK) - 2CWKK)* + C«H»N»0« + 3NH«. 

Mellonlde of (>amelurate Ammelide. 

poUMium. ofpotMsium. 

The potassium-salt is prepared by evaporating a mixture of 1 pt. mellonide of po- 
tassium, 10 pts. potash-ley of spedfic gravity 1*2, and 20 pts. water at the boiling heat, 
the water bein^ renewed as it evaporates, till the concentrated mass is no longer 
curdy, but exhibits crystals on its surface, and the liquid solidifies on cooling to a 
magma of needle-shaped ciystals. These are washed, first with potash-ley, then with 
alcohol, and reczystallised from boiling water. On cooling, the cyamelurate of potaa- 
sium crystallises in colourless prismatic needles having a glassy lustre. Its aqueous 
solution mixed with hydrochloric acid deposits cyameluric acid as a white powder, 
and on dissolving this in boiling water containing a few drops of hydrochlonc add, 
the cyameluric add crystallises on cooling in white crystalline crusts, containing a few 
separate crystals in the form of prisms with pyramidal summits. 

Crystallised cyameluric add contains 2 J at (16*9 per cent) water of crystallisation 
its formula being 2C*H*N'0' + 6 aq. ; the whole of this water is given off at 100° C. 
The crystals dissolve in about 720 pts. water at 17° C, more readily in hot water : the 
solution reddens litmus. The dry acid, exposed to a moderate red heat, turns yellow, 
gires off vapours of cyanic acid, and yields a white sublimate, probably consisting of 
cyanuric acid, with a yellow residue of mellone (tricyanuramide). 

ZCm*^0' = 9CHN0 + CN". 
Cyameluric Cjranic Mellone. 

acid. acid. 

Cyameluric acid boiled with nitric add yields a crystalline product, probably cyanurio 
add. 

CTAMBLrBATBS. Cyamelurio acid is tribasic, and forms three clats^ of salts, 
viz.; nnttrai OT trimrtallic « C«N'M»0*; dimetalHc « O'N'IIM'O* and monomettdlio 
= C^'H'MO'. It unites directly with bases and decomposes carbonates. Strong acids 
decompose the cyamelurates, separating cyameluric ada. 

Cyamelurate of Ammonium crystallises in needles, which are very soluble in 
wat^r, and fall to powder when exposed to the air, giving off ammonia and leaving 
an add salt. 

The Barium-salt, 2C^Ba*N'0* + aq., obtained by boiling a dilute solution of the 
potassium-salt with excess of chloride of barium, ciystallisos in microscopic needles 
Tery slightly soluble in water, and giving off the greater part of their crystallisation- 
water at 100° C. 

The Cupric salt is bluish white, granulo-cr}'8talline, soluble in ammonia. The 
Ferric salt, precipitated from a perfectly neutral solution of ferric chloride by cyame- 
lurate of potassium, forms a yellow bulky precipitate resembling ferric phosphate. The 
Maffnesium-salt is a white crystalline predpitate insoluble in water, soluble in 
sal-ammoniac 

Cyamelurates of Potassium, — The tripotassic-salt, C*K*N'0* + 3 aq., prepared 
as abore described, forms white shining needles often several inches long, has a strong 
alkaline reaction, tastes soapy at first, then bitter and irritating. It dissolves in 7'4 pts. 
water at 18° C, and in 1 or 2 pts. of boiling water, but is insoluble in alcohol. The so- 
lution predpitates the alkalis and alkaline earths. The air-dried salt gives off 8 at. 



Ids 



CYAMETIIINE — CYANAMIDE. 



irater when lell over oil of Titriolor heated to between lCM)**and 120** C, ; ut a low red 
heat^ it inolt^ g:iviiig oflT first amrooniai^l, afterwarda stdd Tapotmi. The dipotas$ic 
»alt^ CTC*HK'0' ^ 2 aq., separates from a modenit<?lj Btrong and slightly wBrmed solu- 
tion of the preceding, on additioii of acetic acid, m tliin lamina*, iridescent ia snn- 
shine. From a boiling solution, it crjst^dliBefi by slow cooling in concentric groups of 
crystalline needles. It is somewhat more soluble in watj?r than cyamflnnc acid, 
and has an acid reaction. The crystaJlisation-water 13 given off between 120° and 
130^ C. The salt when heat-ed to redneas leases a yeUow-brown fiisible reaidne. 

The BittfeT*i&lt^ CN'AgK)* + aq,, is obtained by precipitation, as a white curdy 
snbetance, forming when diy a white friable mass, sparingly actlnhle in dilute nitric 
aeid. It retains a small quantity of water at 130° C. When ignited it leaves metallic 
silver. 

The Sodium- a alt, obtained by decomposing carbonate of sodium with cyamdurie 
acid, crystallises in needles, very soluble in water. 

CTAJVESXHnrs. C'H'N', A crystalUsable organic base, polymeric with cyanide 
of methyl (CN.CH*), and homologous with cyauethine (C*H"N"* p. 189), produced^ 
with evolution of carbonic anhydride, by the action of chloride of acetyl on cyanat^ of 
potassium : 

3(C'E»0,Cl) + 3CNK0 = 3KCI + SCO* + C«H»N«. 

It baa not been analveed, bat ita composition is inferred from the analogy of the re- 
action to that of chloride of benzoyl on cyanate of potassium, by which c^phenine 
(g, V.) ia produced. (Cloez, Ann. Ch* Pharm. cxv, 27). 



CN'BP 



= ^H^S^- 



(Binoau, Ana Ck Phys. [2] Ixrii 368; Ixx. 

26 L — Cloez and Cannisxaro, Ann. Ch* Pharm. Ixxriii 228. — ^W, Henke. ilnd. 

cri, 280.^ — ^Beilstein andGeuther, t W. eviil 88 Streeker, Handw, d. Chem. 

ii. [8] 286.) — Bineaa, by mixing dry ammonia-gas with gaseous chloride of 
^^nagen, obtained a product which be regarded as ammonio-chloride of cyanogen, 
CNCK2NE'. Cloex and Cannizzaro (in 1861) showed that this substance was a mix- 
ttipe of sal-ammoniac and cyanamide (NH^Cl + CN'H'), and obtained the amide in the 
pure state by passing gaseons chloride of cyanogen into a solution of ammoiiia>gas in 
anhydrous ether, Sal-ammotdac then separates out, and the ethereal solution, evaporated 
over the water-bath, yields pure cyanamide. For preparing larger quantities of 
eyanumide, it is better to paas dry ammonia-gas and cliloride of cyanogen simul- 
ti&neoiiBly into anhydrous ether. Liquid chloride of cyanogen, and the bromide and 
iodide of cyanogen likewise yield, with ammonia-gaa, mixtures of ammonium-salt and 
cyanamide, A compound identical in compoaition with cyanamide, and exhibiting 
similar reactions, is obtained by the action of earbonic anhydride on sodiunida 
(Beilatein and Geuther): 

CO* + 2NH«Na ^ 2KaH0 + CWH*. 

Cranamlde is a white aystalline body, which melts at 40^ C, of^en remaining Hquid 
when oooled seTcral degrees low^, and then solidifying suddenly by contact with a 
solid body, When heated to 150*^ C, it solidifies, with considerable cvolntioQ of heat> 
and is contested into the polymeric compound melamine, or cyanur amide, C*N*H'. 
Pyanamide is permanent in dry air and dissolves easily in vmter, but on evaporating 
the solution, it is converted into an insoluble body, probably m eliim i ne. It disitolves 
easily and without decomposition in ahokol and in anhi/drous itfwr. AlKalU decom- 
pose it ; with some addt^ especially with nitric acid, it forma cp'stalline compund". 
On addicig a amidl quantity of nitric iicid to its aqueous solution, nitrate of urea is 
produced : 

CN«H» -I- H^ - CN«H<0, 

A solution of cy&namiife, mixed with nitraie of xiltxr and a small quantity of ammonia, 
yields a floeculont yellow precipitate (? argen to-cyan amide, CN'Ag*), soluble in am- 
monia and in nitric acid. A solution of cyanamide and acetstU of coppur yiehis, on 
gradual addition of potash, a brown bulky copper-compound, (Beilstein and 
Geuther.) 

Cyanamide mixed in an aqueoos Bolutjon with glycoccl (CNH*0*), unites wiOi it, 
fanning glycoc^amine, CN'H*0" a base homologous with creatine, wb'ch separates 
afler some days in colourless crystalliae ncedlen, (Strecker,) 

SM/bgUtuHon-dtfrivativet 0/ Cyanamidr. — These compotiniis, derived from cyanamide 
by the snbstitntion of 1 or 2 at. of an alcohol*radiele for an e<jiuivalent. quantity of 
hydrogen, are obt&tned by the action of chloride of cyanogen od ethylaniine, phenyl- 
amine, ^ The ethyl and phenyl compounds are the only ones that Imve bee^n 
studied. (See CiAjrETSriAMiDB and CrAyoPKBKTULKiDS,} 



I 
I 
I 



J 



CYANETHINE— CYANETHOLINE. 189 

Btcymno-diamlde, G^^H^ ^ HM ^'' ^ aqueous solution of cyanamide left 
to itself for some time, or more quickly if mixed with a small quantity of ammonia, 
deposits a sparingly soluble substance, crystallising in broad laminse, and apparently 
consisting of dic^ano-diamide, the molecule of which is simply that of cyanamide 
doubled. It unites with nitrate of silver^ forming the compound C^*H*. AgNO*, which 
crystallises in yery slender needles, very soluble in boiling water, sparingly in cold 
water and in nitric acid. The solution of this silver-compound mixed with ammonia 
yields a whit« insoluble pulverulent precipitate consisting of C*N^H*Ag. 

Dicyano-diamide dissolves in acidSj the solutions yielding by evaporation ciystalline 
Baits of the base C^^H'O. The hydrochlorate, C«N*H»O.HCI, forms colourless 
needles, and its concentrated solution yields with dichloride of platinum^ a crystalline 
wecipitate, C^*H*O.HCl.PtCl*, which crystallises from hot water in large prisms. 
The nitrate, C«N*HK).HNO» (at 120° C), crystallises in colourless needles grouped 
in hemiroheres. The oxalate (C^*H»0)'.C*H'0*, is formed on adding a warm con- 
centrated solution of oxalic acid to a solution of dicyano-diamide, and crystallises on 
evaporating the liquid. Its formation is attended with copious evolution of carbonic 
oxide and carbonic anhydride, arising from decomposition of part of the oxalic add 
added. The sulphate (C«N*H«0)^H»SO* + 2 aq. crvstallises in needles which give 
off their water at 100<» C. The base, C*N*H«0, is obtained by heating the solution 
of the sulphate with carbonate of barium, and evaporating the filtrate, in colourless 
crystals having an alkaline reaction, easily soluble in water, slightly in alcohol. When 
boiled with water, it is decomposed, with evolution of ammonia, and formation of a 
base which appears to belong to the type NH*.H.O, inasmuch as, when treated with 
Imlrochloric acid, it is converted into a chloride, with elimination of 2 at water. 
(Haag; Handworterbuch, loc, cit.) 

TaXCTANO-TBIAJCIDB, C^*H'. See CTAKrUAHIDB. 

CryAlfllXaTHYL a Hm>g, See CYAi^THYLAinDE. 



Crr^rarBZVB. C*H^«N'. (Frankland and Kolbe, Chem. Soc Qu. J. i. 69 ; 
Ann. Ch. Pharm. Ixv. 288)— An organic base, polymeric with cyanide of ethyl (CN.CH*), 
and pvobably having the constitution of a triamide, N*.(C*H'*)'" (Hofmannj. 
It is obtained b^ the action of potassium on that compound. Hydride of ethyl is 
erolved with brisk effervescence, and a yellow viscid residue is obtained, consisting 
of cyanide of potassium mixed with a small quantity of cyanethine, from which the 
cyanide of potassium may be dissolved out by cold water.* It is difficult to account 
for the evolution of hydride of ethvl in this reaction, unless it be supposed that the 
potassium used was mixed with hydrate of potassium. 

<>anethine crystallises from boiling water in white nacreous scales. It has no 
smeU, and very little taste, melts at 190° C, and boils with partial decomposition at 
280°. Cold water dissolves it very slightly, boiling water more freely, alcohol in all 
proportions. The aqueous solution has a faint alkaline reaction. Cyanethine may be 
boiled and even melted with potash, without alteration. 

Cyanethine dissolves easily in all acids, forming salts which have a rough and slightly 
bitter taste, are soluble in water and in alcohol, and oft«n crystallisable. The acetate 
gives off acetic acid when evaporated in vacuo, and is converted into an insoluble 
basic salt. The hydrochlorate and the sulphate are very soluble in water, and un- 
ciystallisable. The chloroplatinate, C»H"N'.HCl.PtCl», is obtained by precipitation as 
a reddish yellow ciystallme salt, moderately soluble in alcohol, less in water, and 
crystallising therefrom by evaporation in large ruby-coloured octahedrons. The al- 
coholic solution is decomposed by evaporation, yielding chloroplatinate of ammonium. 
The nitrate, C*H'*N*.HNO*, ciystallises in large colourless prisms, which are perfectly 
neutral. The oxalate forms fine prismatic crystals. 

CrrAnTBOIiZVB. G^*NO. (Cl oez,Compt rend. xliv. 482; Ann. Ch. Pharm. 
ciL 354.) — An organic base isomeric with cyanato of ethyl (CN.CH*.0), produced by 
the action of gaseous chloride of cyanogen on a solution of ethylate of sodium in 
absolute alcohol : 

C*H*NaO + CNCl = NaCl + C»H»NO. 

On decanting the liquid from the deposit of chloride of sodium, and distilling it in the 
water-bath, cyanetholine remains as a syrupy liquid of specific gravity 1*127 at 15° C, 
which may be freed from chloride of sodium by washing with water. It Jin s a 
faint odour, like that of sweet oil of wine, and a disacreeablo bitter taste. It is 
insoluble in water, but dissolves in all proportions in alcohol and other. It is deoom- 

* The quantltj of cyanethine obtained by the process abore described is extremcijr small : it might 
perhaps be obtained more readiljr br a process analogoua to that bv which Cloes has obtained cjaphe- 
nine (f. v.), vis. by Che action or chloride of propiunyi on cy anate or potassium, 
3C»H*0CI + 8CNK0 - 3Ka + 3CO« + C»H»N». 



190 



CYANETHYLAMIDE — C YAI^IC ACID, 



poBcd by distillatioa, l<?nving a rurl>onapeoiis peeidue. By Ijoiling with atrong potasli- 
ley it in decomposiMl, vntU ovoUition of ammoiMii (? othykmiEe), Wten mtric oxide is 
paiified int^i aBolution of the base iu nitric ad d^ nitrogen 18 evolved, and a cryatidlisablo 
«abi«t4infe, tiat yet examined, m deposited. 

Cyaiiftlioliiie diBsolves in jtcids. forming Malt-H ttIucIi ore mo«tIy ciTBtaHisablc Tho 
eki&n^plaiinaie ia yellow. The nitrate forms with nitrate of silver a double salt wMch 
feparates in large crystals. The sulphate crystallises in small prismB when its solution 
11 ©vflp4>nit^d over od of vitrioL 

CN V 
GTAVBTKY^AIUXSS. C'N*H* » C^H* ^ N. (CQoez and CilnnieKarOt Ann. 

Hi 
Ch, Pharm. IxxviiL 288.) — ^I*roda(?ed by tho iiction of gas^otu chloride of cyanogen on 
ethylamino t 

CNCl + 2C'H'N - CH'N.HCl + CWH*. 

It ifi a woak base, uniting with conct^ntrated acids, and forming compounds wbieh. 
are decomposed by water. At ISO'^ C. it is resolved into cyandiethylitinidc, which 
diistils over at that tcmpt^rature, and a solid amber-coloured body, which volatilises 
without decomposition at SOO*' C. The ktter m a feeble base, C*N*H*, which fomui 
with hydrochloric add and didiloride of plat burnt »* crystalline compound, nearly ia- 
solublfl in water, but easily Boluble in ulcohob ospcciaUy when hejited, and separating 
in Une yellow scales on cooling. 

C^anduthylumid^ Q^^W^ ^ iT'lT^I'f^* — Produced a« just mcation<?dj by tho 

decomposition of eyanetbylandde : 

Also by passing chloride of cyanogen into a solution of diethybimine in anhydrout 
ether* 

It is a colourless liquid which boils at \W^ C>, and is decomposed by acids and 
tJkalis into carbonic anhydride, water, and diethylaruine: 

N.CN.(C^H*)' + 2H'0 = C0» + NH" + N(C=H*)«.IL 

Ciaudiethylantlde. Diettajknalue. 

CTAJriO ACra. CNHO = ^^Io,or ^^^^ [n. (Wohler, Gilb, Ann. btxi. 95; 

Ixxiii. 15.^ — Pt'gp. Ann. i. 117; t. 335; Ann.Ch. Pharm. xlv. 351,— Liebijr, Kastn. 
Areh. vi. Ho; 8chw. J. xlviii. 3T6 ; PogR. Anii,x^\ 6GI, 619.— Liebigand Wobler, 
Pi*^g. Ann. %x. 369. — Bai*yer, Ann. Ch, Pbarm, exiv. 156. — Briining^ ihitL civ. 
198.) — This acidt originullv distlnguislbfld by the name of c^au&us add (cyanuric acid 
l>eing then reganled as a higher oxide of cyanogen and calle<l Cf/anic a^«<2), was jELrst 
notieud by Vaugutlin in 1*518. afterwards obtained in a more deflnit* state and 
examineil by Wohler in 1822, It is produced: a. In the free st^ite: 1. By heating 
the polymeric compound, cyanuric acid, C'N'H'O^ which then splits up into 3 atoms 
of cyanic acid 2. By heating ureA (cyanate of ammonium) with phosphoric anhydride 
to 40** C, the mixture then rimtig spontaneously in temocraturo to 130® — 140°, and 
yielding a distillate of cyanic acid mixed with cyamcbde (Lie big). 3. By the diy 
distllktiou of xanthamide (stilphocarbamate of ethyl), which tht^ splits up into mer- 
captan (sulphydrate of ethyl) and cyanic acid (Debus): 

CHINOS - C-H«S + CXHO. 

Xjinihajnlde. Mercaptan. Cjnnic acid. 

4. By heating niio arid with peroxide of manganese and sulphuric add (Boberoiner 
Oilb, Ann. l^iv. 121). 6. By heating mercuric urate to rednews (Wohler.) 

h. In combination with bases ; 1. By passing cyanogen gas into solutions of the 
aUcalia or alkaline earths, or by heating an anhydrons allaJine carbonate to low redness 
in f^anogen gas, or with an anhydrous metallic cyanide^ such as cyanide of mercuiy t 

2CN + WO ^ CNIMO -f CNM 
Tj-JUialG. Cyanide. 

2. By fusing a cyanide or ferrocyanide of an alkali -metal in contact with the air, or 
vrith easily redudbl*^ oxides (snch as oxide of linid) or with peroxide?, or with small 
quantities of nitrat4*8, 3. By the electrolysis of a solution of cyanide of potassium, 
the cyanate being then formed at the positive polo (Kolbe). 4. By igniting nitre 
with exceiss of finely divided charcoal* 6. By adding melam, ammeline, or ammeHdo 
to melting potash-hydrate as long as it dissolves (Liebig). 6. By heating sulpho- 
cyanato of ethyl with |sotaah4ey, the products bdn^ cyanate of potassium, cyanide of 
potassiiinii and disulphide of ethyl (Briining) : 

2(CNaC?H') + K'O - CNKO + CNK + C*E}m 



CYANIC ACID. 191 

7. A BolatioD of urea mixed with nitrate of silyer and evaporated, yields cjanate of 
HilTer. 

Preparation. — Cyannric acid, previously dehydrated, is heated in a small retort to 
eommencing redness, and the evolved vapour of cyanic acid is condensed in a receiver 
tarroimded with a fireezing mixture (Wohler). The distillate thus obtained is 
always more or less clonded by the presence of the insoluble polymeric compound, 
cjamelide (CN'H'O*^ which likewise sublimes in the neck of the retort together with 
nDaltered cyanuric aad. The loss of product thus arising may be diminished, accord- 
ing to Baeyer, by heating the cyanuric acid in a tube bent at right angles, and laid in 
a combustion-furnace, in such a manner that the heat may reach the bend during the 
whole of the process, the heating being commenced at the bend and gradually extended 
backwards. It is best also to pass a stream of carbonic anhydride through the tube 
daring the process. 

Cyanic acid cannot be separated from its salts in the ordinary way by the action of 
aqueous acids, because it then immediately takes up water and splits up into carbonic 
acid and ammonia. It may, however, be obtained by passing dry hydrochloric acid 
over diy cruiate of silver and collecting the evolved vapours in a cooled receiver. 
(Wohler, Pogg. Ann. v. 386.) 

iVv»p«r^W.— Cyanic acid ia a thin, colourless liquid, which reddens litmus strongly, 

and has an extremely pungent odour, like that of glacial acetic acid, and somewhat like 

that of sulphurous acid. The vapour excites a copious flow of tears, and causes violent 

smarting in the hands. A drop of the liquid acid instantly produces a white blister, 

attended with severe pain ; indeed, it is almost as dangerous to work with as strong 

hydroflooric add. 

CN) 
Cyanic acid may be regarded either as a hydrate of cyanogen ^ C ^' ^^ ^ carbimide 

„ ( y. The first of these formuLe exhibits most clearly the relations of cyanic acid 

to bases and to other acids ; the latter, its decompositions in presence of water, the 
decompositions of the cyanic ethers by alkalis, &c. 

Decompositions. — 1. The Liquid acid changes spontaneously into cy am elide (in- 
soluble cyanuric acidj, a substance which is polymeric with it, the change taking place 
the more quickly, ana with greater rise of temperature, in proportion as the substance 
is less cooled. At 0° C, the acid changes in an hour, and without explosion, into dry, 
hard, snow-white cyamclide ; but if it be removed from the frigorific mixture, so that 
it may assume the ordinary temperature, it soon becomes turbid and mill^, begins to 
boil, thickens to a pasty consistence, and becomes continually hotter, till it explodes ; 
the paste is then scattered about, and changes completely into cyamelide. At ordinary 
temperatures, the conversion is complete in five minutes ; it Ukewise takes place as 
quickly under increased external pressure as under the ordinary pressure. Vapour of 
cyanic add mixed with an inactive gas appears to remain unchanged for a long time 
(Liebig and Wohler). 2. The acid, mixed with water, splits up spontaneously in 
a short time, at ordinary temperatures, into 1 at carbonic anhydride and 1 at. 
ammonia, the add reaction of the liquid then changing to an alkaline reaction, and 
a smell of ammonia being produced. (Wohler.) 

N.C&Jtt + HH) « Cb.O + NH». 

Whilst one portion of the cyanic add is thus converted into add carbonate of 
ammonium, another portion takes up the ammonia, driving out the carbonic anhydride 
with effervescence, and forms cyanate of ammonium, which, on evaporation, is con- 
verted into urea; and a third part of the add is converted into cyamelide, and 
separates in white flakes. This decompodtion is likewise attended with evolution of 
hMt (Liebig and Wohler). The aqueous add, when prepared by bringing cyanie 
add vapour in contact with ice, in a receiver surronnaed with ice, remains neariy 
unaltered at the temperature of 0°, giving off but a few bubbles of carbonic anhydride 
(Liebig and Wohler.) A considerable quantity of water retards the decompodtion 
of the add into carbonic add and ammonia; the presence of one of the stronger 
adds accelerates it, by virtue of the affinity of that add for the ammonia ( W o h 1 e r Y. 
3. The aqoeooB add is decomposed by Btdphydrio acid (Liebiff). 4. When cyamo 
add vapour ia passed into meihylic, ethylic, or onty/tc alcoM, the corresponding 
ailophanic ethers (i 133) are produced: e.ff, 

CTEK) + 2CNH0 - C«H»(C«H»)NH)«. 

"'* *■ " "lophanaU 

ethyl. 



EthTlic Cjanic Allophanate of 



These ethers were originally mistaken for cyanic and cyanuric ethers (Liebig and 



192 



CYANIC ACia 



Wohler). 5- With antydpons aldtht/de^ cyani** jicid fomui trig on ic acid, ynih 
eTolution of c4irbomc nahydride (Liebig and Wohler,): 

C*H*0 ^ SGNHO = C*e^N»0» + CO'. 

6* With qli/€of^ ghiecrin^ and e\iqtnic acid^ cyanic acid reacts in the aamo manner as 
with alcohol (Baeyer). 7. Wkb valtraldt'h{fdi\ it forms a compound homologous 
with trigenic acid, 8. When cyanic acid Tapour m passed into trieih^lphoBphine^ no 
change of com position takea place in either body, hnt the cyanic acid is polymerised 
into cyan uric acid, which settles down aa a white deposits (Hofmann, Chem. See. 
Qn. J, xiii. 322.) 

Hydrochloraie of Ct/anie acid^ CNHO.HCl, — When dry bydrochloric acid gas is 
passed throngh a long tube containing well-dried cyanate of pottisaium, great heat is 
produced, and a colom-lcss Hqnid distils over. This reaction is always oceompanied by 
tlie prodQction of cyamcHtle, which remains behind on dissolving the chloride of 
calcium in water j and, if the cyaoat-e of potassium be not kept cool, we obtain* instead 
of the aboTf-mentiooed distillate, nothing but a mixture of cynmclide and hydrochloric 
acid* Cyauate of silver upppare to b« better adapted for the preparation than the 
potassium-sal t (Wohler). The compound is a traD§i>iirent and colourless tiquiri 
wbich fumes strongly \i\ the air, and smells Tcry strongly of cyanic and hydrochloric 
acid. 

Enclosed in a scaled ^ass tube, it remains unaltered at 0^ C. ; but, at ordinary 
temjjeratureSr it solidiEes in a few days into a cryatalliue mass^ coiLsifiting of sal-am- 
moniac and cyamelide* the solidificAtlon being accompanied by the eTolution of highly 
compressed carbonic and hydrochloric acid gases (Wohler), The compound, hejit4Hl 
in open ve^^ads, k resolved into cyamelide and hydrochloric acid gas. It dissolres 
immediately in water, yielding a solution of sal-ammoniiiCi with great rise of tempe- 
ra tm-e and yiolent erolutioa of carbonic anhydride : 

CNHO.HCl + WQ = NH*C1 + COl 
Hence it immedijitely begins to effervesce when eipoaed to moist air, or when breathed 
upoii^ the decom[)Osition going on till nothing remainis but a solid mass of sal-am- 
nifjuiuc. When mixed with alcohol, it decomposes immediately, with great evolution 
of heat, into hydrochloric acid and alhphanic ether. (Wuhler, Ann. Ch. PhiiroL 
xlv. 357.) 

Cyftuatea. Cyanic acid ia monobasic^ its salts having the formula ClOiO or 

CN I 

^50. They are ohtained, sometimea by the methods indicated for the formation of 

cyanic acid (p. 191) i sometimes by bringing the aqueous add in contact nith the bnse ; 
sometimes by precipititting an aqueous solution of cyanat© of potassium or barium with 
a heavy metallic suit (Wohler). In the last case^ however, according to Haidlen 
and Fresenius, a carbonate is sometimes thrown down instead of thecyanate, e.g. with 
lead and sciuc salts* 

Many cvanateSj as those of stiver and mercury, when heated in the dry state, 
give off undccompoBod cyanic acid, t<>gether with carbonic auhydride and nitrogefi gases ; 
othert^, as those of the fixed idkaii-mctals, remain uudecomposed even at a red heat, 
excepting in presence of moisture, by which the salt is decomxx^ed, at a moderate 
heat, into carhouate of ammonium, fixed alkaline carbonate, and a substance re- 
sembling pamcyanogen \ the same decomposition is produced oven by repeated solution 
in water and evapomtiou : 

2CICK0 + 3H«0 ^ K-O + 2NH» + 2C01 

Cyanates are decompoped by the stronger acids^ the cyanic acid being wholly or partly 
decomposed by the water prt^sent, into carbonic anhydride and ammonia, so that the 
reaction is attended mth effervescence, and the liquid, if subsequently heated with 
excess of |>otaSih, gives ofi' ammonia. The pungent odour of cyauic acid is always more 
or \mB perceptible. CNpanatea detonate when heated with chlorat* of potassium 
(Wohler). Strong solphnric add, dilute hydrochloric acid, and aqueous oxalic acid 
elimiaat« &om cyamites scarcely any but cartxtmc acid, retaining the ammonia ; crys- 
tallised oxaUc add, or oonoe&trat4>d hydrochloric acid, expels cyanic add, which is then 
converted into cyamelide* Dilute sulphuric acid eliminates, together with the carbonic 
add, a quantity of imdccomposed cyanic acid vapour, which may bo recognised by its 
ibt^nsely pangeat odour. Some acid^.as acetic acid (and likewise mitterai acidst 
e. g, hydrochloric acid^ according to Campbell), if added to the concentrated »ohition 
of the potassium -salt, likewise throw down crystals of acid cyanurate of potassium 
(Wohler). Tho odour of cyanic acid is slowly, and therefore most perceptibly, 
evolved on dissolving cyanate of potassium in water coiituining cream of tartar. 
(Hiincfeid, Sehw. J, lx.477.) 



CYANIC ACnX 193 

The cysnates of the alkali-metals, alkaline eaxih-metids, and a few others, are 
■ohible in water. The solutions form white precipitates with nitrate of lead or silver, 
or with mercuraus nitrate^ greenish-brown with nitrate of copper, and brownish-yellow 
with chloride of aold (Wohler). They do not form any precipitate with stannoua 
or stannic chlorioe, fenons or fierrio chloride, or with mercnrie chloride. Neither do 
they form pmsaian blue with iTon-salts, on addition of solphydric acid or sulphate of 
ammonium. 

Cyanates of ^mm^ntttm. — The neutral salt CN.NH^O, which is isomeric with 

carbamide (urea), h«[^> ^'^ ^^^ heen. prepared in the solid state, but may be ob- 
tained in solution by decomposing cyanate of silver with aqueous sal-anmioniac The 
filtered liquid exhibits the reactions of a cyanate, but when heated or left to eyi^rate 
^K»taneously, it is converted into urea. 

Basic salt. — ^When vapour of cyanic acid is mixed with dry ammonia-gas, the two 
condense, with great evolution of heat, to a snow-white powder, very soluble in water. 
The solution, when evaporated, gives off ammonia, and deposits urea. The dry salt 
undergoes the same transformation, gradually on exposure to the air, immediately when 
heated ; in an atmosphere of ammonia it may be preserved unaltered. (Wohler.) 

Cyanate of Amy I, — See Ctanio Ethebs. 

Cyanate of Barium, CNBaO, ma^ be obtained by passing cyanogen-gas into 
bazyta-water, whereby cyanate and cyanide of barium are produced, decomposing the 
oranide with carbonic acid, and removing the carbonate of barium by filtration 
(Wohler); by mixing concentrated aqueous solutions of cyanate of potassium and 
acetate of barium, and adding alcohol, which throws down a precipitate of cyanate of 
barium (Berzelius) ; or most easily by heating cyanurate of barium in a retort till it 
melts (Berzelius). The salt crystallises in small prisms. Its aqueous solution is 
decomposed by boiling, into ammonia and carbonate of barium. 

Cyanate of Calcium, — Obtained by passing C3ranic acid vapour into milk of lime. 
It does not crystallise. 

Cyanate of Copper, — Greenish-brown precipitate, obtained by mixing the solu- 
tions of cyanate of barium and acetate of copper. 

Cyanate of Ethyl, — See Ctahic Ethebs. 

Cyanate of Lead, CNFbO, is obtained by mixing the solutions of acetate of lead 
and cyanate of potassium, as a white precipitate composed of fine needles, and soluble 
in boiling water. When heated in an open vessel, it takes fire, bums with sparkling, 
and leaver metallic lead. 

Cyanate of Methyl, — See CrAino Ethkbs. 

Cyanate, Mercurous, — ^White precipitate, obtained by adding a solution of the 
barium-oalt to mercurous nitrate. 

Cyanate of Potassium, CNKO. — For the various modes of formation of this salt» 
■ee page 190. It is prepared by oxidising the cyanide with metallic oxides : 1. Crude 
cyanide of potassium, prepared by fusing the ferrocyanide with carbonate of potassium, 
sad containing 6 at. cyanide of potassium to 1 at. cyanate, is heated to the melting 
point in an earthen or iron crucible ; somewhat more than three times the quantity of 
polverised and gently ignited litharee is then introduced, the fused mass beine stirred 
at the same time ; the mixture is heated till the metallic lead has collected at the 
bottom, then poured out ; and the solidified saline mass is pulverised and boiled with 
alcohol as long as the resulting solution continues to yield cyanate of potassium on 
cooling (Liebig): 

CNK + Pb*0 - CNKO + Pb*. 

Acooidinff to Clem m (Ann. Ch. Fharm. IxvL 382), the best mode of preparing cyanate 
of potassium is to add 15 parts of minium, by small portions at a time, to the fused 
and somewhat cooled, but still fluid mass of 8 pts. ferrocyanide and 3 pts. car- 
bonate of potassium, taking care that the temperature does not rise too hign. The 
cradble is then to be returned to the fire, and the contents stirred, poured out, and 
left to oooL — 2. A finely-pulverised mixture of ferrocyanide of potassium and per* 
oxide of manganese is raised to a very low red heat (if the heat be stronger, the 
cyanic acid is decomposed, with formation of carbonic anhydride and protoxide of 
Banganese) (Wohler). 0^ an intimate mixture of 1 pt. crystallised ferrocyanide of 
poCasaiam and firom li to 2 pts. manganese, is formed into a cone, the point of which 
M set OD flze by a red-hoi ooal, whereupon a slow combustion extends throughout the 



194 



CTANIC ACIB. 



mMs (Lielsig). Orbptter: a T<?ry fliioly-pulreris^Ki and intimate mixhare of 2 pts. 
dehydrated ferroeyftnidB of potuRsium and 1 pK mangmiese i» beatecl to low redDeaa 
on an iron plate, Trith constant stimiig^ the ujaea gradually burning with a glimmcriiig 
light. The 03cygen of the manganc>«e ui fir from enfflcient for the formation of the 
cyonatc of potasBinin, but the air likewise tak^s part in the action ; if more manganeae 
be used, a (*oaBiderabIo quantity of carbonat43 of potasi»iiim ia prijduced (Lie big). 
— 3. An intimate mixture of 3 pta. dehydrate f^etrocynnidc of potas^iinm, I pt dry 
carbonate of polaanvuii, and 4 pt«. Tery fiaely pounded manganese, is gently ignited in 
a emcible till a sample dissolTed in Tirater aft<^r cooling nf> longer forms FruBsiiio blae 
with ferric salts. The mass, when ooM, is finely pounded and boiled with 80 per cent, 
of alcohol (Beffelius, Lchrbtmh), — 4. A mixture of 4 pta. ferrocyanide of potas- 
Bium and 3 pta. nitre,, is thrown bj smiall portions into a ri?d-hot crucible, Stjrong 
detonation then takes place, and there remains a black mixture of undecompoj^ed 
ferrot»yanidn, chaneoai ferric oxide, and carlsonate and cyanato of potassium, the 
qiaantJty of the latter amounting to 1 part. (Wohler.) 

To obtain the eyanate of pokis»Ium in a purer state from the residues of these 
processes, they mnst be boiled with alcohol of the strength of 86 per cent, as long as 
the roaulting liquid continues to ^ield cyanate of potaAsitim on cooUug. The alcoholic 
mother-liquid serrca to repeat the exhaustion of the residue. The crystals must he 
scTcml times washed with absolute alcohol, prejaed, rapidly dried at 100*^ C, or in 
Tacuo over oil of vitriol, and preserred in a well- closed bottle, because the salt is very 
easily resolTed by the action of moisture into cubonute of ammonium and acid carbonate 
of potassium. (B e r x e li u s. ) 

Cjanate of potassium crystallises in small colourless laminio and needles^ similar to 
those of chlorate of potaftsium. It fuses at a temperature much below redness to a 
transparent and colourless liquid. It ia inodorous, and tastes Hko nitre. (Wohler.) 
It dissolves readily in water^ sparingly in cold bydrated alcohol, more easily in boiling 
hydrated alcohol ; in absolute alcohol it is insoluble. (Wohler.) 

The dry salt is not decomposed by ignition ; but ifimUrhe dropped upon it at that 
temperature, it is rapidly resolved into carbonate of potassium and carbonate of 
ammonium. The same change takes place whtiu an aqueous solution of the salt is 
evaporated in the air, either at the ordinary or at a higher tempemture (Wohler) : 
2CKK0 + 4E^0 « CO'K' + CO'.(NH*)*. 

Hydrogen gas passed over the red-hot salt, abstracts all the oxygen atid reduces it to 
cyanide of potassium ; hut the water thereby produce^! decomfK>ses another jiortion of 
the cyanato of |>otassium into carbonato of |>otasaium and carbonate of uunnonium 
(Wo hie r). Charcoal at a red heat likewise converts eyanato of potassium info cyunido 
(G m e 1 i n). Pofassium dissolves quit^ quietly in melting cyauate of potaasiuiii, forming 
a mixture of potash and cyanide of potassium : 

CNKO + K* = CNK ^ K'O. 

Red-hot iroH'-filings form, with the salt, a mixture of cyanide of potassium, ferro- 
cyanide of potassium, and pr<:>toxide of iron (Wohler). Sulphur fuses with the Bidt, 
forming a mixture of sulphocyanate, sulphide, and sulphate of potassium (Wohler). 
In this ea**c., other decomponition-products are prohably formed at \hv sanu^ time. — 
Sulphuric acid converts the m* llini salt into a yellow mtiture of sulphide ami salpho- 
cyauhteof pota>isiuni, a ^mall quantity of sulphydrat^^ of ammonium being sublimed at 
the same time (Wohler.) Dry hydrocldoric acid ga^^ passed over the heated salt* 
produces sal-ammoniac and chloride of potassium (Wohler); probably also phos* 
gene is formed at the aome time : 

CKKO + 4HCI ^ KCi + NH*C1 + CCIO. 

When cyanafce of potassium is heated with chtoridt ofhencof/!^ earbonie anhydride 
is evolved, and chloride of potassium is formed, together with cyaphenirie, a crys- 
talline base polymeric with cyanide of phenyl (benzonitrile), and a smidl quantity of 
an oil Ixiilitig at 190'^ C.« which uppeare to be cyanide of phenyl: 

3C'H=0a + 3CNK0 = 3KC1 4- 3C0* + C^^H^'N*. 
Chlorldt? of Cfniiittt} of C>-apl»vi]lne. 

tienfojrL iJOtouium. 

A similar reaction takes place with chloride o/acftf/l^ carbonic anhydride being evolved 
and a crystalline kise produced, probably oy am e thine, C*11'K' (p. 200). (Clocf 
Ann. Ch. Pharm, cxv. 27.) 

Ci/anatu of Silper^ CKAgO, is obtained by decomposing cjanate of potiissinm 
with nitrate of silver, as a white precipitate, of specific gravity 4004, and somewhat 
B^iluble in boiling water. Dilute nitric acid dissolves and immediately decomposes it 
When heated^ it meltsi, bums with incand*M9cence, and leaves charcoal and metallic 



I 
I 



CYANIC ETHERS. 195 

nlTer oontuning nitrogen. It dissolves in ammonia, the solution yielding by eyapora- 
tioQ, large semitransparent ciystalline laminse, consisting of ammonio-cyanato of 
silyer, or cyanate of argentammonium. When exposed to the air or immersed 
in water, they give up their ammonia and become opaque. (Wohler.) 

Cyanate of Sodium ia crystallisable. 

Cyanate of Yttrium. — Anhydrous salt, insoluble in water and in alcohol; sepa- 
rates after a while £rom a mixture of the alcoholic solutions of cyanate of potassium 
and an yttrium-salt. (Berlin.) 

CTAVZC gTII BBBi These compounds, the cyanates of the alcohol-radidefl, 
are obtained by distilling cyanate of potassium with ethyl-sulphate of potassium, 
or by the action of the iodides of the alcohol-radicles on cyanate of silver. They are 
volatile liquids which give, with potash and with ammonia, reactions analogous to 
those of cyanic acid (cyanate of hydrogen), yielding, in the first case, carbonate of 
potassium, and an ammonia in which 1 at. hydrogen is replaced by an alcohol-radicle, 
and in the second, a carbamide, or urea, in which 1 at. hydrogen is similarly replaced. 

Cyanate of Allyh C*H»NO - CN.C»H».0, or N.Cb.C»H». (Cahours and 
Hofmann, PhiL Trana 1867, 566.) — Produced by the action of iodide of allyl on 
cyanate of silver. The heat produced by the reaction is sufficient to distil over nearly 
the whole of the volatile product It is a transparent colourless liquid, having a pun- 
gent and intensely tear-exciting odour. It boils at 82° C. Vapour-density =- 3-046 
(ezp.) « 2*88 (calc. 2 yoIs.) It dissolves easily, with rise of temperature, in ammonia, 

db ) 
and the solution when evaporated yields crystals of allyl-urea, ;g$/nsTT»\r^'* With 

etkylamine, in like manner, it yields ethyl-allyl-urea. Distilled witn potash it 
yields allylamine, N.mC»H*. 

Cyanate of Amyl C«H»'NO « CN(C»H")0, or N.CO.C'H". (A. Wurtz, Ann. 
Ch. Phys. [3] xlii 43.) — Prepared by heating 2 pts. of amylsulphate with 1 pt 
cyanate of potassium : 

C»H".KJSO* + CN.K.0 « K«SO« + CN.C*H".0. 

If a small quantity of mercury be added to the mixture, it may be distilled rapidly 
over the open fire. The distillate, if rich in cyanate of amyl, is tolerably mobile. 
When purified by rectification from a small quantify of a less volatile compound, it 
boils at about 100° C. With ammonia it yields amyl-urea, N^.(CO)".C*H»MI*, and 
when hcateil Mnihpotaeh it yields amylamine, N.H^C^H". 

Cyanate of Ethyl Cyanic ether. C»H»NO = CN.C»H».0, or N.Cb.C«H». 
(Wnrtz, loc. cit^ — Obtained, together with cyanuric ether, by distilling cj-anate of 
potassium with the ethylsulphatc. The cyanic ether is easily separated by rectifica- 
tion, being very volatile, whereas the cyanuric ether, which has a triple atomic weight, 
does not hoW. till Riisod to a very high temperature. It may be purified by several 
rectifications over chloride of calcium. 

Cyanate of ethyl is a transparent, colourless, very mobile liquid, of specific gravity 
0-8989, and having a very high refracting power. iJoils at 60- C. Vapour-den- 
sity = 2-476 (exp.) « 2-460 (calc 2 vols.) The vapour is very irritating, and excites 
a copious flow of tears. 

I}fcvmpositions. — 1. Cyanate of ethyl is decomposed by water into carbonic anhy- 
dride and diethyl-carbamide: 

2(N.(50.C«H») + H«0 = C0« + N«.CO.(C^»)«.H». 
2. It dissolves in aqueous ammoniOy the solution yielding by evaporation beautiful 
prisms of ethyl-carbamide : 

N.C&.CH* + NH» - N«.C&.C'H».H«. 

With ethylamine, phenylamine, conine, &c., it yields, in like manner, carbamides in 
which 2 at. hydrogen are replaced by alcohol-radides, e, g. 

N.db.C*H» + N.H^C«H» =. Nl(5b.C^H».C«H».H«. 
Cyanate of Phenjlamine. PhenyKcthyl-carbamide. 
ethyl. 

8. Boiled with ^potaeh in a sealed tube, it yields carbonate of potassium and e thy la* 

mine: 

N.C6.C«H» + 2HK0 = C(5.K«.0» + N.CH».H» 

Cyanate of Carbonate Ethylamfne. 

•tliyl. ofpotaMium. 

o2 



196 



CYAKIC ETHERS. 



4. Hcat«d in lite maimer with anhydrous etktflaie ofmiium {^ pottunum) it yielda 
tj^iethjlaminer 

Somptiroos, however, a difiweDt ppaetion takc« pWe, jielding carbotri ethyl tnamine an<! 
other ppoducta (Hofmann, pp. 654, fiflO).— 5. Cyiiiiate of ethyl mUed idih gladcd 
actiic addf yields carbonic anhydride and cthylacetamide : 

N.Cb.CH* + C*H»O.H.O - C0» + N,(CH»0)lCr-H*. 

6. Hwitedto 180^ C. in a sealed tube with acetie anhydride ^ it yields ethyldiaeela- 
mide; 

N.C'5.C*H* 4- ((7H*0)'.0 = CO^ + N.(C?«H»0)'.C*H*. 

7, When cyanic ether is mixed with cnn<;eatmt6d./brwiiic acid^ -riolent ©Tolution of ear- 
boDic anhydride takes place, and if the tube b« then Hf'alHl and heated to 100° C** 
ethyl- form amide, C'H' NO = N. CHO. C*H«. H, \b produced. — 8. With akokol^ 
cyonjite of ethyl forms cthylcarbamate of ethyl (ethyl-urethane): 



It does not act upon Hhtr, eTcn when strongly heated with it in sealed tubes for aevend 
ijjiyg^ — g^ Cyanate of ethyl dii«3olves urea (^jarbomidc) at a moderate heat, and the sob- 
tioHi heated to 100° C, for about a quarter of an hotir, and then left to cool, eoHdiSiia 
to a crystalline mass, chiefly coneiating of the comf>o!iud C'H'*N*0\ formed by the 
union of I at. carbamide (CH*N'^0) and 2 at. cyanic ether f C"H^NO). This compound, 
which crystallises fkt}m hot water in white silky needles, anadisaolvas i^cadily in alcohol. 



ether, and dilttte acids, is diethyl<tric&rbo-tetram 



(CO)* ) 
ide, (C='H*)'^N*; it eont^na 



also the elements of diethyl-cyanurate of ammonium, (0«^i\ti^H*.p** ^^^ ^* 
doo« not ex hi Vat the characters of an ammonium-sAlt, not yielding di ethyl cyannrie 
acid when treated with mineral scidst or being precipitated by dichlonde of plaf ilium, 
or giTing off ammonia when treated with cold potash^ in which indeed it dissolves 
without decomposition ; it is only when boiled with potash that it suffers decomposi- 
tiou, being then resolved into 2 at. ammonia, 3 at. ethylamine, and 3 at. carbonic an- 
hydride (Hofmann, Proc. Roy. St^c. xi 274). — 10. Cyanate of ethyl, mixed with 
^ricMy/pAo^/FA/rtf, is gradually converted into cyan urate of ethyl ^ the odour of 
the cyanate soon disappears, and if the liquid be then treiited with dilute hydrochloric 
acid to remore the pnoEiphoruS'biiSE5, the oil which floata on the surface quickly 
Bolidifies to a crystalline mass of cyaunric ether, (Hofmann, Chem. Soc Qu, J. 
xtii. 322.) 

Bt/drochl<>rate of Cyanic Eth^^ C'H*N0.HC1. — Obtained by passing dry hydro- 
chloric acid gas into cyanic ether, or by the action of that gas on diethyl-carbaniide : 
C*H»'N20 + 2HC1 = C'H*N0.HC1 + C^H^'.HCL 

Dtrtthjl- Hydrocblorate of llTdrnchl'Tate 

carbamide. cjanic eiher, or «tbyl*inlne. 

It 18 likewise the chief product of the action of chlorine on ethybcarbamide. It is a 
liquid which has a punpent ttMLT-exciting odour, boils at 95°' C.» and l*i immediately 
decomposed by water, yielding carbonic anhydride and hydrochlorate of ethylamine, 
(Habich and Limpricht, Aiin. Ch, Phann. cv> 396.) 

Cyanatf ofMtlhiik C^*NO =- CN.CH*.0, or N.CO.CH*. (WurtE, loc.cit.)— 
Obtained by heating 2 pts. of crystaUised and well dried methyl-sulphat*! of potassinm 
with 1 pt. of cyanate of potassium, collecting the distiUate in a well cooled receiver, 
and reetifying to separate the cyanate of meth^rl from the much less Tolntile cyanu- 
rnt^ formed at the same time. It is a rery Toktilc liquid, boiling at &0^ C, and emit- 
ting highly pungent choking vapours. When sealed up in a tube, it changes in a few 
weeka^ and often indeed in a few hours, into crystallised cyannrate of methyl. Its re* 
actions with potash, ammonia, water, &c., are analogous to those of cyanate of ethyl 

Cyanate of Nuphthyl, C^'H^J^O « CN,C'*H^O, is obtained, together with other 
products, by the action of phosphoric anhydride on dinuphthyl-carbamide. (V, Hull 
Proc. Ray. Soc, ix. 366.) 

Cyanate of Fhrnyl, Anitocyamc Acid, Carhanil, AnUcarbamide, Phcnyl-carh- 
fnidt^ (TH'NO * CN.C'H\0 ^ N.cdC*H\— This compound, discovered by Hof- 



A 



CYANIDES. 197 

maon in 1860 (Ann. Ch. Phann. Ixziv. 91 was originally obtained by the dry 
distillation of melanozimide ^C**H"N*0'). Tnis substance, when heated, suffers a very 
complicated decomposition, giving off lar^ quantities of carbonic oxide and a small 
quantity of carbonic anbjdnde, and yielding a distillate of cyan ate of phenyl mixed 
with diphenyl-carbamide (see Mslanoxhcidb). The latter ciystallises out as the 
distillate cools, and on filtering the liquid and rectifying in a p<^ectly diy apparatus, 
the cyanate of phenyl is obtained pure. C^anate of phenyl is also produced in small 
quantity by the dnr distillation of melaniline (Hofmann, loc. cit) More recently 
Hofinann has found that it may be obtained by the action of phosphoric anhydride, 
chloride of cine, or strong hydrochloric acid, on diphenyl-carbamide, the substance then 
tplkting up into phenylamine and cyanate of phenyl : 

N».c6.(OB7.H« - N.C«H».H» + N.C6.C«H\ 

Diphenyl-caiW Phenylamine. Cyanate of 

mtde. phenyl. 

the decomposition bein^ precisely analogous to that of carbamide (urea) into ammonia 
and cyanic acid. As diphenyl-carbamide is difficult to prepare, it may be replaced for 

this purpose by diphenyl-oxamide, N.C?0'.(C*H*)*.H*, which, under the influence of 
phosphoric anhydride, splits up into carbonic oxide and diphenyl-carbamida (Hof- 
mann, Flroa Boy. Soc. ix. 274.) 

Cyanate of phenyl is a thin, transparent, colourless, strongly refracting liquid, 
heavier than water, and boiline between 1 78° and 180° C. Its vapour has an extremely 
powerfiil odour of cyanogen, hydrocyanic acid, and phenylamine together, exciting a 
eopioos flow of tears, and producing a feeling of suffocation when inhaled. 

In contact with acids or alkalis^ cyanate of phenyl takes up 1 at water, and is re- 
solved into phenylamine and carbonic anhydride : 

C^H»NO + H«0 - C«H'N + C0«. 
With Strang sulphuric acid, the products are carbonic anhydride and phenyl-sulphamic 
add: 

CrH*NO + H^SO* » C0« + (>H^SO». 

With waUr^ cyanate of phenyl yields carbonic anhydride and diphenyl-carbamide : 
2(N.db.C»H») + HK) « C0« + N«.Cb.(C^»)^H«. 

Cyanate of phenyl. DlphenyUcarbaroide. 

With ammonia^ it evolves great heat» and immediately solidifies in the form of phenyl- 
cazbamide : 

KCb.C^» + NH« =» N».C6.C«H».H». 

With phenylamifUj it also becomes heated, and yields a solid mass of diphenyl-car- 
bamide: 

N.db.CH* + N.C^».H« - N».C5,(C«H»)«.H». 

Other organic bases, such as hentylamine^ chinoline^ cumenylamine, &c., likewise form 
with cyanate of phenyl, solid products which appear to be analogous to diphenyl-car- 
bamide. In contact with trietht/lphosphine^ it is converted into solid cyanurate of 
phenyl. (Hofmann, Chem. Soc. Qu. J. xiiL 322.) 

Cyanate of phenyl dissolves in methylic^ ethylic, amylic^ and phenylic al^^ohoh, the 
liquid becoming hot, and depositing, after a while, splendid ciystals, which mell at the 
heat of boiling water, are insoluble in water, but dissolve in all proportions in alcohol 
and ether. The bodies thus obtained have not been analysed, but they appear to be 
the phenyl-carbamates of methyl, ethyl, &c. ( H o f m a n n.) 

cnrAJfXBBS* Compounds of cyanogen (CN, or Cy), formed on the hydrogen-type 
HH, or more generally nHH. The foUowing are examples : 

Cyanide of Hydrop;en (Hydrocyanic acid) . « • . H.Cy 

Cyanide of Potassium ECy 

Cyanide of Ethyl C«H».Cy 

C^^anide of Mercury* Hg"Cy' 

Cyanide of Zinc and Potassium 2n ( ^y* 

Cyanide of Ferricum (Ferric cyanide) .... (Fe*)'"Cy' 
Cyanide of Potassium and Ferrosimi (Ferrocyanido of) K*frt-» 

^Potassium) .$ Fe»J^ 

Cyanide of Potassium and Ferricum (Ferricyanide of/ K* >^ . 

Potassium) {(Fe^)^ 

Cyanide of Potassium and Cobalticum (Cobalticyanide of / K* > p„« 

PotaMiiim) J(Co«rr^ 

• Hff. a= 300. 



198 



CYANIDES. 



CymJn|d«ft, Bfetaliti). These compoundi flfe not found in natme readj farmed^ 
Irat are prodnced in nnmerons processes : 

L A tew metals, potAfiaiam amontt the nnmbci*, are converted into cynnides when 
heated in cjranogen gas or vapour of hydrocyanic acid, in the latter ease with separation 
of hydrogen. — 2* Cyanogen gas, passed over the heated hydrates or carbonates of the 
alkali-metals, forms a mixture of cyanide and cyanate of the metal; it acta in the sumo 
Aaoner on solntioDs of the fixed alkalis, excepting that a brown suhetanee like para* 
ejaoogcn is abo formed. — 3. When nitrogen gas is passed over a ntixtnre of charcoal 
and hydrate or carbonate of potussiain at a bright red heat, cyanide of potasaium is 
formed (Fownes, J. pr. Chem. xxvi. 412; Wohler, JahTi?8ber, d, Chem. 1850, 

g660; Rieckhon, Ann* Ch. Pharm. Ixxix, 77 1 Belbruck, ibid, Ixiv. 296. — 
unsen, Hcports of the Britiah Association, 1845, p. 135). Cyanide of potassium alao 
exudes from blastrfomacca in which iron -ores arc smelted with charcoal. — 4* Cyamdea 
are formed abundantly when nitrogenous organic compounds, or the nitrogenoujs char- 
coal obtained &om them, aro ignited with flxed alkalis. This is the nrincipal method 
by which cyanides are prepared on the large scaie, e.g. ferroeyaniae of potassium, 
by fusing carbonate of potassium with iron Mings and wastes animal matter. The 
same reaction is naed for the det<H!tion of nitrogen in organic comi>ounds (i. 225). 

6. Cyanides are also formed by igniting nitrat-es or nitrites with organic substances, 
dthcr nitrogenoos or non-nitrogenons : thus, nitre, fused with excees of tartrate or 
ftoeiate of pctt^ssium, yields a considerable quantity of cyanide. — ^6. Cyanide of am- 
moninm is formed when a mixture of ammonia-gas and carbonic oxide is paascd 
through a red-hot tube ; 

2NH» + CO -^ CN.NH* + H-Q ; 

also when ammonia-gas is passed over organic bodies, charcoal, or oven gmphite, at a 
red heat, the reaction being attended with elimination of hydrogen : 

2>rH» -J- c=c:n.kh' + h«, 

or sometimes according to Kuhlmann, of mai«h-gas: 

4KH* + 3C = 2(CN.KH^) + CH*. 

7. Cyanides are formed one from the other by double decomposition. Hydrocyanic 
acid converts metallic oxides into cyanidea, sometimes anhydrotia, as in the case of 
silver, but more generally hydratcd. To convert an aqneons alkali (which shotild bo 
free from carbonic acid) completely into cynnide, hydrocyanic acid must be added to it 
till it no longer precipitates sulphate of nm^mesium. Soluble cyanides treat*:'d with 
nitrate of silver yield a precipitate of cyanide of stiver, and the precipitate, digested 
with the aqneous solution of an alkaline protofulphide, yields snlphide of aQvcr and 
cyanide of the alkati-metaL 

Prifperties and ^factions, — The cyanides of the alkali-metals are easily soluble in 
water, bat most cyanides of the heavy metals are insoluble ; cyanide of mercorTt how- 
ever, is aoluble. The cyamdcs of the alkdi -metals, cyanide of merewry, and many 
double cyiiuides containing it^ are soluble in dcohoL None of the metallic cyanides 
are soluble in ether. 

Some cyanides are crystallisable. Some are colourless, others exhibit various colours. 
The cyanides of the alkali -metals in the state of aqueous solution, exhibit u stn^ng 
alkaline reaction, and have a bitter and alkaline taste ; the solution zefmains alkaline, 
even when mixed with a very lai^e excess of hydrocyanic acid. 

Cyanide of ammonium, or hydi^yanate of ammonia, Tolatihscs undecompoeed when 
hcat*d. The compouuiis of cyanogen with the alkali- metals sustain a red heat without 
decomposition^ provided air and moisture be excludedL The cyanides of many of the 
heavy metals, e. g. lead, iron, cobalt, nickel, copper, &c, under these circumsTanccs, 
give off all their nitrogen in the form of gas, and are converted into a compound or 
mixture of 1 at, metal and 1 at, carbon: CNM = CM + N. — Cyanide q^ mercurj' is re- 
aolvcd into mctitllic mercuiy and cj'anogen gas ; and cyanide of silver gives ofl' half 
ita c^ranogen in the gaseous fonn, the other half, perhaps converted into paracyanogen, 
remaining combined with the Hilver. 

All cyanide*!, when heated in the presence of waler^ are destroyed, those of the 
hcEivy metals generally giving off carbonic oxide, carbonic anhydride, and ammonia, 
and leaving the metal, together with a small quanltty of charcoal. The cyanides of 
the aQudi-metais are converted by continued boiling with water into ammoniacal giis 
and alkaline formates^ c. g, : 

CNK + 2H=0 =. KH* + CHKO* 

The cyanides of some of the alkali-metals, e, g. cyanide of potassium, when heated 
in contact ^-ith the air, ftret take up I at oxygen, and are conveiiiKi into cyanutes 
(CNKO), and theae, when further heated, give off nitrogen and half the carbonic 
anhydride formed, and aro converted into alkaline carbonates. The cyanidee of the 



CYANIDES. 199 

htKwj metals take fixe readily when heated, yielding nitrogen, carbonic acid, and metal 
or oxide. Cyanides detonate by percusaion with cMorate of potaaainm. (Johnston, 
Sefaw. J. Ivii. 379.) 

Chlorine gas decomposes many cyanides, converting them into chlorides, and liberat- 
ing cyanogen, chloride of cyanogen, either fixed or Tolatile, and a yellow oil, the pro- 
ducts Tarpng according to the presence or absence of light and water, the nature of 
the cyanide, and the proportion of chlorine present : e, g, 

HgfCy* + Cl« - Hg^Cl* + 2CyCl. 

Chlorine, gndnally introduced, converts cnranide of lead or cyanide of silver into 
netallic chloride and free cyanogen, which does not take np any chlorine till all 
cyanide is decomposed (Liebig, Pogg. Ann. xv. 571). Aqueous chloride of lime acts 
wpim cyanide of silver with violent raervescence, evolving carbonic acid and nitro^n, 
together with a small quantity of cyanogen ; but no cyanic acid is formed (Liebie). 
Mine forms metallic iodide and cyanogen, or iodide of cyanogen. It decomposes the 
cyanides of the alkali-metals in the state of aqueous solution, also cyanide of silver or 
cyanide of copper dissolved in aqueous cyanide of potassium, forming a metallic 
iodide and lihgting cyanogen (G-erdy, Compt rend. xvi. 25; also J. pr. Chem. 
xzix. 181). With boiling aqueous cyanide of potassium, it forms iodide of potassium 
and iodide of cyanogen (Liebig, Ann. Ch. Pharm. L 335). It decomposes diy 
cyanide of mercury, forming iodide of mercury and iodide of cyanogen. 

Strong nitric acid decomposes all metallic cyanides, with evolution of carbonic acid, 
nitrogen, &e. Excess of strong sulphuric acid decomposes metallic cyanides at high 
temperatures, forming a sulphate of the metal, acid sulphate of ammonium, and carbonic 
oodiie (Fownes): 

2CNM + 8H»S0* + 2H«0 - M«SO« + 2(NH«.H.S0*) + 2C0. 

Most cyanides, when treated with dilute adda^ give off their cyanogen in the form 
of hydrocyanic add : e. y. 

KCy + Ha « Ka + HCy. 

The cyanides of the alkali-metals, which, in the state of aqueous solution, may 
ibo be regarded as hydrocyanates, are decomposed by the weakest acids, even by 
carbonic acid ; hence their solution, if it does not contain excess of alkali, gives off 
hydrocyanic acid on exposure to the air, that acid being gradually expelled by the car- 
bonic acid of the air. On the other hand, it is only the alkaline sulphydrates and soap- 
solutions that are decomposed by hydrocyanic acid. (Scheele.) 

The compounds of cyanogen with the heavy metals are of a more intimate nature. 
Some, as the cyanides of zmc and lead, give off hydrocyanic acid when treated with 
dilute solutions of the stronger mineral acids, such as sulphuric acid ; others, as the 
cyanides of mercuiy and silver, are not decomposed, even by the strongest oxygen-acids, 
in the state of aqueous solution ; but hydrogen-acids, such as hydrochloric and sulphy- 
dric acid, decompose them ; others again, as protocyanide of gold and protocyanide of 
iron, withstand the action of dilute sulphuric, hydrochloric, or nitric acid, even at a 
boiling heat. 

From the solutions of the alkaline cyanides, many heavy metallic oxides separate 
part of the alkali-metal, in the form of oxide, which remains dissolved, forming at the 
same time a heavy metallic cyanide, or a compound of that cyanide with the cyanide 
of the alkali-met^ : 

2KCy + H^O + H«0 - Hg"Cy» + 2KH0. 

The cyanides of some metals form crystallisablo compounds with the oxides of the 
same metal ; with various metallic iodides, bromides, and chlorides ; also with nitrates 
and chromates. 

Double Cyanides. — Cvanides have a strong tendency to unite with one another, 
and form definite compounds, called Ctfanogen-salts^ or Double Cyanides (analogous 
to the iodides, bromides, and chlorides), e,g. cyanide of nickel and potassium, 
KCy.NiCy « KNiCy* ; ferrocyanide of potassium, 2KCy.FeCy = KTeCy*. (See Table 
p. 197.) 

The most numerous of these double salts are the compounds of the alkaline cyanides 
(including cyanide of ammonium, NH*Cy), with the cyanides of the heavy metals ; they 
are form^ and prepared as follows : 

1. By saturating the aqueous solution of the cyanide of an alkali-metal with a heavy 
metallic cyanide, or, if the latter be soluble in water, adding it to the. alkaline cyanide 
in the proportion determined bv calculation. — 2. By saturating the a<^ueous solution 
of the alkaline cyanide with a heavy metallic oxide or hydrate. In this case, part of 
the alkali-metal is separated in the form of hydrate, which remains mixed with the solu- 
tioo, and t2i« heavy metal passes over to the cyanogen-compound : 
SKCy + FeHO - K«FeCy» + KHO. 



900 



CYANIDES, 



8. Bjr digeatmg & Heavy metnllie cyanide with an aqtieoos allcalL Id tMs case, on tlie 
eontnrjf {Mut of the heavy metal is separated in the form of hydrate : 

SPeCy + 2KH0 « K^eCy* + 2PeH0, 

4. By addint; aqneotut hydrocyanie acid to a mixhiref is eqniralent proportions, of a 
heaTy metallic oxide or iti carbonate, and a cattstic or carbonated alkali, till the acid 
jretains its odour even alter bog agitation at a gentle heat In thij caae, the hydro- 
eyanie a<nd driTea oat all the carbonic acid that may bo present, and the heavy 
metallic oxide is diasolved.^ — 6. By saturating with cao^ic potoah or carbonate of 
potaasiamf the acid oompound which hydroCTanic acid forms with certain heary 
metallic eyanidaaL — 6. Flatinoeyanidea may be formed by fosiog platinum with 
cyanide of potassium. In this case, part of the cyanide of t)Otaasium is decomposetl, 
yielding cyanide of platincun and free potassinm (which oxioisea to potash), while the 
nndccomposed portion of the eyaoide c^ potassinm nnitea with the cyanide of platiniun 
i^mned. 

The pfoporlioDS in which the heavy metallM! cyanides may thoa be made to imite 
with the cyanide of an alkali-metal^ e.g. with cyomde of potaaslnm, are the fol- 
lowing: 

a. 3 at. Cyanide of potasaimn to I at Hemicyanide of a heaty metal, ZKCy.Cu*Cj ^ 

K»Cn*Cy*. 
A. 1 at Cyanide of potassinm to I at Hemicyanide of a heavy metal, ECy.Cn^Cy. 
c; 2 at Cyanide of potassium to 1 at Piotocyanide of a heavy metal, 2KCy.Fe^, 
if. 1 at Cyanide of potasaiom to 1 at Protocyanide of a heavy metal^ XCy«^Cy ; 

KCy.CdCy; KC^.NiCy; KCyJlgCy; KQrJLnCy; KCy.PtCy; KCyJ*dCr. 
Jt 1 at. Cyanide of potassinm to 2 at Protocyanide of a heary metal, ECy.2PeCy. 
/. 2 at Cyanide of potassitun to 1 at Sesqnicyanide of a heiiTy ipetal, 2KCy.Pt^CV*< 
a. 3 at Cyanide of potassinm to 1 at Sesqnicyanide of a heavy metal, 3KCy.Cr^^' ; 

3KPyJtfn^y*; SKCy^FeH^; 3KC^.Co»CV*; 3KCy.Ir*Cy«, 
£ 1 at Cyanide of potassinm to 1 at Tricyanide of a heaxy metal, KCy^AuCy*. 

Almost all these double cyanides an^ crystaUisable and solable in water. Townrda 
vegetable colours they ore nentnd or slightly alkaline, whereas the pure cyan idea of 
the alksU-metals have a strong alkaline reaction; the double cyaniaea likevrise emit 
little or no odour of hydrocyanic acid. They are also much lees easily decomposible 
than the pure cyanides of the alkali-mrtals* 

Both the metallic cyanides contained in these compounds beharev wheii ignited in a 
dose vessel, just in the same manner as when they are ignited separately. Thus, in 
ferrocyanide of potassinm, 2ECy*FeCy, the cyanide of potassium remaius nndecom- 
po'H'd, while the cyanide of iron is resolved into nitrogen and carbide of iron. 

By adds the double cyanides are decomposed with various d<*grees of facility. The 
alkali-metal is always CHBily withdrawn, and its place supplied by the hydrogen of the 
acid. With many double cyanides^ however, this change takes place without any 
alteration of structure in the molecule, thus : 

K»FeCy« + 2Ha - HTeCy* + 2KCI. 

F^rrocjriinldlo Ferrocj-xnlde 

of potSMittco. of bydrofva. 

In other cases, only the alkaline cyanide is decomposed, with evolution of hydrocyanic 
acid, whBe the heavy metallic cyanide separates out; s.^. 



KAgCy» 
KAgCy« 



HNO» 
HQ 



AgCy 
AgCy 



HCy + KCl. 



If the separated cyanide is likewise decomposible by the acid nsed^ an exoeas of the acid 
metnally produces this decomposition, eliminating the whole of the cyanogen 
hydrocyanic acid : 

KAgCy* + 2Ha * 2HCy + AgCl + KCl. 
2K2nCy* + 2H*S0* ^ 4HCy + Zn*SO< -j- K-SO** 

In other cases, the excess of the add produces no further decomposition, as when 
Cyanide of silver and potassiim is acted upon by nitric acid : 

KAgCy' + 2HN0" ^ AgCy + HCy + KNO> + HKO'. 

Snlphydric acid prfM:ripitatcs the heavy metal, in the form of anlphide, from the dis- 
iolved compounds of the alkaline with the heavy cyanides, sometimes easily, as with 
cadmium, meicnry, and silver ; sometimes not at ail, or but slowly and portiaUyj as with 
line, iron, cobalt, nickel, and copper. 




CYANIDES. 201 

"When the solution of sach a eompoand of a cyanide of an alkali-metal with the 
cyanide of a hear^ metal, is mixed with the salts of other heavy metids, precipitates 
are formed, exhibiting strong and yaried ooloors, and generally consisting of com- 
pounds of the heaT^ cyanide already present, with another heavy cyanide formed by 
double deoompositaon between the cyanide of the alkali-metal and the salt of the 
beayy metal which has been added. Thos, feirocyanide of potassium forms with sul- 
phate of copper a red prec^tate of ferrocyanide of copper : 

K«FeCy» + Cu«SO« « Cu«FeCy» + K«SO«. 

Bat these pedpitates often retain part of the original cyanogen-salt in a state of inti- 
mate oombmation, so that in many esses it cannot be com^etely extracted even by 
boiling water. 

On acoonnt of the different behaviour of the several double (^anidcs with acids, it is 
usual to divide them into two classes. 1. The easily decomposible double cyanides, which 
give off hydrocyanic acid when treated with a stronger acid, even in the cold. These 
are regarded as true double salts, that is to say, as compounds formed by the addition 
of two simple cyanides, e. g, cyanide of nickel and potassium, ECy.NiCy. — 2. The less 
easily deeomj^osibU double cyanides^ which, when treated with acids, do not evolve hy- 
dnxTanic acid, but merely exchan^ their alkali-metal with the hydrogen of the acid, 
as is the case with the double cyamdes of iron, chromium, cobalt, and manganese. In 
these compounds, the cyanogen is usually supposed to be more intimately combined 
with the heavy metal, forming a compound radicle, which, like chlorine or cyanogen 
itself; can unite with metals, forming salts which are decomposed by acids, and yield the 
hydrogen-salt of the same compound radicle. Thus, the yellow cyanide of iron (fer- 
rosum) and potassium, ETeCy', is regarded as the potassium-salt of the radicle 
ferrocyanooen, FeCy* « CN*Fe, usually denoted by Cky ; hence it is called /rrro- 
cyanids of votassium. In like manner, the red cyanide of iron (ferricum) and 
potassium, C*N*Fe*K' « K'Fe'Cy*, may be regarded as ferri- or fcrrid-cyanide of 
potassium, E'.Fe'Cy^ or E'.Cfdy, a compound of potassium with ferri- or ferrid- 
cyanogen, FeK!^. Similar compound radicles are supposed to exist in the double 
cyanides of chromium, cobalt, and manganese. 

This view of the composition of the second class of double cyanides is convenient, 
when a particular class of reactions is under consideration, viz. the interchange of 
the alkali-metal of the double cyanide for hydrogen, or for a heavy metal ; but it is 
by no means necessary to regard them in this way ; in fact, the behaviour of a double 
cyanide with acids appears to depend rather upon the peculiar nature of the heavy 
metal contained in it tnan on any particular molecular arrangement The first stage 
of the decomposition is the same m all cases, the alkali-metel being replaced by hy- 
drogen ; but the hydrocyanic acid thus formed remains, in some cases, combined with 
the heavy metallic cyamde, while in others it separates : 

KNiCy« + HNO« - NiCy + HCy + KNO« 
KTeCy* + 2HC1 - FeCy + 2HCy + 2KCL 

If now we turn our attention to the reactions which take place when these double 
cyanides are decomposed by metallic salts, instead pf by the corresponding acids (hy- 
drogen-salts), e. y* 

K*FeCy» + Cu^SO* - Cu'FeCy* + K»SO* 
2KNi(y + Cu«SO« - 2CuNiCy« + K-SO* 
KCdCy» + Pb.C^»0* - PbCdC^« + KC»H«0», 

we find that the combination or separation of the resulting cyanides is not determined 
by the constitution of the original double cyanide, since the components of the same 
doable cyanide (cyanide of nickel and potassium for example), may separate when the 
aDiali-metal is replaced by hydrogen, whereas, when it is replaced by a metal, the re- 
Bolting cyanides remain united. 

Neither can any difference of constitntion in the two classes of double cyanides be 
inferred from the fact that some of these compounds, containing two heavy metals, 
the cyanide of nickel and coppor, for example, are decomposed by acids, whereas 
others, as the cyanide of iron and copper, are not, this difference being due rather to 
the different nature of the metals present. Prussian blue, which is a ferrocyanide of 
iron, Fe'Cv*, or (Ffe*)'* Fe*Cy*,* produced by the action of ferrocyanide of potassium 
on sesquichloride of iron, is not at all attacked by dilute acids, whereas, if one portion 
of the iron existed within the radicle and the rest without, the latter portion might be 
expected to disaolve in adds while the former remained. 8o likewise with the different 

• Ff« B r^. 



202 



CYANIDES. 



b^'havioiir of double cyanides with sulplijdnc add j it is the nature of tb© heavy metal 
that determines whether decorapo3itioa nhaJl take place or not, mther than anj pecu- 
liarity of mokculitr constitution ; thaa, cadmium, mercury, and silver are easily precl- 
pitut^d by salphydric aeid from Bolutioua of their doubl^^ oyanidea ; niekel, copper, zinc, 
and raanganeae alowly and Tery imperfectly ; iron and cobalt not at all 

With alkafiSf the Tarious double cyamdea exhibit, for the most part, similar reac- 
tions. Those which contain alkall-metala are not decomposed at all by allcolis, eren 
at the boiling bent. Those which oontalu only heayy metals, ftajTocyanido of copper 
and the pmssian blues for example, are decomposed In such a manner that part of tho 
heavy metal is replaced by an alkali, so that a soluble double cyanide is formed, and 
a metallic oxide separated; but these deeom positions often take plaee in such a 
manner aa to show that no particular part of the metal is more iotimat^^ly com- 
bined with the cyanogen than the rest j thiifl ferricyanide of iron (Tumbnirs blue), 
Fe^y*, or Fe'Ffc'"C^*, yieldj with potaab, not ferricyanide of potassium and ferroua 
oxide, but ferrocyanide of potassium and ferroso-ferric oxide. 

Mt^rvnric oxide and mercuric sulphaU decompose all double cyanides, exc4*pt tho 
pjatinoeyanides ; thus, ferrocyiLuido of pottissium and pruasian blue are completely 
conTert«d by them into cyanide of mercury, with formation of oxides or sulphates of 
iron. 

All cyanides which give off prussic acid when treated with dilute acids, such as 
cyanide of potassium, c^^anide of nickel and potassium, &c., ar^ poisonoua, like proscdc 
acid itself, whereas the more stable cyanides, Uko ferrocyanido of potassium, are not at 
all poisonous. 

Gjanlile* of Aicobol-radloles. Cifanhydfie or Eydrocynnic Kth«ra. These 
eompQunds may be regarded either as analogous in composition to tho metallic cyanides 
(if- as hydrocvauic acid having its hydrogen replaced by an alcohol-nwlicle), or \is tho 
niiriUa of acid radicles containing 1 at. carbon more thao the aloohobradide in com- 
bination with the cyanogen: thus, 

Cyanides eontainif^ the Aleohol'Tadicks, C'^H^<*+^ 

Cyanide of Methyl, or Acetonitrilo . . . C^H*N « CHlCy. 
(Sranide of Trichloromethyl, or Ghloraceto- 

nitrile C«C1'K - CC1".C^, 

Cyimido of Ethjl, or Proplonitrile , , . C"H*N ^ C'Tl*.Cy. 

Cyanide of Tetrjd, or Vakronitrile . . , C»H''N ^ C*H".Cy. 

Cyuiido of Arayl, or Caprouitrile . • , C*H"N= CH^'-Cy. 
&c» &c 

Cyanides coniainittg the Jlcohol-radicUSf C^IP'—'', 



Gyfuiide of Phenyl, or Benzonitrile 

Cyanide of Nitrophenyl, or Nitro-benzonitrile 

Cyanide of Benzyl 

Cyanide of Cumenyl, or Cumonitrile 



C^H*N ^ CH^.Cy. 

C«H^N - C^H'.Cy. 
C"H»*N - C*H'l(5y. 



Tho cyaaides of the alcohol-radicles are obtained i 1. By distilling a mixtiiro of 
cyanide of potassium with an ethyl-sulphate (or homologous salt), e.y. 

KCy + C«H*.KSO* ^ E*SO* + CmKCj, 

2. By tho action of heat or of phosphoric anhydride on tho ammonium-salts of ibia , 
corresponding adds containing the radicles C^H-" -' 0, or CH^ -*0 ■ thus, 

C5H'O(NH*)0 - 2BK>^ C*H«N. 

Ac«tnt<i €r Cymnids of 

ammonliLiiiL. niethjL 

C^H»0(NH^)0 -2HK) - CTI»N. 

Benioate of Cf iiUde of 

amtuoDium. ph«iijU 

This last reaction gives the means of obtaimng cyanides coiresponding to alcohols 
which have not yet been formed. 

The alcoholic cyanides are for the most part volatile liquids, having an odour sou 
what like that of prussic acid. When treated with strong acids or alkalis, they take ' 
up watcr^ and reproduce the ammonla-salt^ from which they may be formed. This action 
is analogous to that of cyanide of hydrogen (prussic acid), which, undar tho influence of 
acids or alkalis, yields 'ammonia and formic acid (CHN + 2H'0 -r KH* + CH*0*). 
In fact, cyanide of hydrogen (or formonitrile, CH.N) may be regarded as the lowest term 
of tho ^noB of homologous aloohoHe cyanides C^H*"' ' N. 



CYANIDE OF ALUMINIUM— CYANIDE OF BENZOYL. 203 

Cjwuaidem of Aeid OnrABlo Xadleles. Two only of these compounds are 
known, viz. the cyanides of benzoyl, CH*0, and cinnamyl, C"H'0. They are obtained 
hy distilling the chlorides of the corresponding acid radicles with metallic cyanides. 
l!heir reactions are analogous to those of the corresponding chlorides. 

CTikinDB OF A&SiTXm C*H*N = C«H* Cy. (Li eke, Ann. Ch. Pharm. cxii. 
816.) — Obtained by heating equivalent quantities of cyanide of silver and iodide of 
allyl. and warming the resmting viscid oil with alcohol or ether, or distilling it with 
water. The product is a limpid mobile liquid, having a disagreeable pungent odour. 
Specific gravity = 0*794 at 17° C. Boils between 96° and 106° C. Somewhat solu- 
ble in water, miscible in all proportions with alcohol and ether. 

CTAJrZBB OV AXiUMZailllM does not appear to exist in the separate state. 
Hydrate of alumina does not dissolve in prussic acid, and when cyanide of potassium 
is added to an aluminium -salt, hydrate of alumina is precipitated finee from prussic acid. 
A forrocyanide of aluminium has, however, been obtainea. (See Ctanides of Ibon.) 

CTJ&JrXDB or AmKOVZVM. Hydrocyanate of ammonia. CN^« » Nll'.Cy 
s NIP.HCy. — Ammonia-gas and vapour of hydrocyanic acid unite in equal volumes, 
without conilensation, and produce this salt. It is likewise formed, as already observed 
(p. 198), when ammonia-gas is passed through a red-hot tube together with carbonic 
oxide, or over ignited carbonaceous matter; also when charcoal in excess is ignited in 
a retort with sd-ammoniac and lime, or litharge. Lastly,«it is sometimes formed by 
the action of nitric acid, nitrous acid, or nitric oxide, on organic bodies. 

Tlie dry salt may be prepared by heating in the water-bath 3 pts. ferrocyanide of 
potassium with 2 pts. sal-ammoniac, tlie materials being perfectly dry, and condensing 
the product in a receiver surrounded with ice and salt Cyanide of mercury or cyanide 
of pi->tassium may also be used instead of the ferrocyanide. Langlois prepares the salt 
by pa.<«ing dry ammonia-gas over dry charcoal heated to redness in a porcelain tube. 

Cyanide of ammonium crystallises in colourless cubes, often grouped like fern-leaves, 
ver}' soluble in water and alcohol. It has a strong pungent odour of ammonia and 
prussic acid together. It boils at 36° C. The vapour is very inflammable and burns 
vith a bluish flame, depositing carbonate of ammonia. The density of the vapour is 
anomalous, the molecule NH'.HCy occupying four volumes instead of two. J3ut as 
hydrocyanic acid unites directly with ammonia, wo may suppose that the vapour of 
nani'le of ammonium is a mixture of these two bodies (the molecule of each occupying 
two volumes), and that the salt exists only in the solid form, being decomposed at its 
boiling point. 

Cyanide of ammonium is very instable, and gradually changes into a brown substance, 
asiJmic acid (L 480). Chlorine and bromine decompose it, forming chloride or bromido 
of cyanogen. 

Cyanide of ammonium is highly poisonous, and yet ammonia is generally said to act 
a^ an antidote to prussic acid ; according to Langlois, the beneficial action is due to 
the stimulating properties of the ammonia. 

CTASriBB or AMYX. Capronitrile, C«IT"N = C^II".Cy. (Balard, Ann. Ch. 
Phy«. [3] xii. 294.— Frankland and Kolbe, Ann. Ch. Pharm. Ixv. 288.— Brazier 
and Gosslcth, ibid. Ixxv. 251. — Med lock, ibid, Ixix, 229.) — This compound is 
obtainM by distilling equiyalcnt quantities of amy Isidphate and cyanide of potassium; 
al.sn by the action of cyanide of potassium on chloride or oxalate of amyL It is a very 
niobile oil, of specific gravity 0*8061 at 20° C, and vapour-density 3-336 (2 vol.). 
Boils at 146° C. ; is less soluble in water than cyanide of ethyl, and dissolves in alcohol 
in all proportions. Boiling potash converts it into ammonia and caproato of potassium : 

CE}^ + KHO + H^O = NH« + C«H"KO». 

Potasf^um decomposeflit, with evolutien of gas, and formation of an alkaloid resembling 
cyancthine. 

CTiLVZlIB OV BABZITM, BaCy, may be obtained in the dry state by igniting fer- 
rocvanide of barium (Berzelius), or ferrocyanide ofbarium and potassium (Schulz), in 
a close vessel, — and in solution, by adding prussic acid to baryta-water till it no longer 
precipitates chloride of magnesium (Ittner). Margueritte and De Sourdoval 
(Compt. rend. L 1 100) prepare it on the large sciilo bv passing air over an ignited mixture 
of carbonate of barium and finely divided carbon : the formation of the cyanide is said to 
take place with great facility. It is very soluble in water (F. and E. Rodgers), 
uparingly (Schulz, J. pr. Chem. Ixviii. 267), moderately soluble in alcohol, easily 
de<\>ni posed by carbonic acid. Heated to 300° C. in a stream of aqueous vapour, it 
gives oflT the whole of its nitrogen in the form of ammonia. (Margueritte and De 
Sourdeval). 

CTAMTBm OV BBHXOTXm C"HK) » CHACON. Already described (L 668). 



204 CYANIDE OF BENZYL— CYANIDES OF CUROMIUM. 

CTAWZDS or asvZT^. Cyanide of Ihl^l or Tdu^^l C"H^ » C^H*.CN. 

(St;e i. 673.) 

CTAJTZms or BISMUTU has not been obtained. Alkalino cy&nides added to 
bkniu-tb-salta throw down anlj oxide of bLamatk, (Haidlen and Fresenitis.) 

CTFAJriiDE or Simf ^ See CTA^vmE op TsTurL, 

crrAJT^iv or qmlo^^wwim* (i 406,) 

OTAVXSfi or CAI>9SJirJI£» CdCj. Obtaiaed in white anhydrotis erf stak b/ 
diflfKilyiiig recently pfectpitiited bjdmte of cadmium, at a gentle heat, in bydrocjaule 
acid. It is periDftneiit in the air. According to EammelfilRrg, cadmlam-Bdts afe not 
precipitated bj alkaline cyanides. Acoordlng to L Gmelin^ on the contraiy (Hundb. 
vii. 426), enlpaate of cadmitim forms with cyanide of pctaasinm a white prfj-clpitato, 
soluble in excess of the cyanide,— a reiult confirmed by the observations of Witts tei n» 
of Haidlen and Fresenitia, and of Scbuler. (Ann. Ch. Pharrn. Ixxxvii. 34,) 

Cf^anidu of Copper and Cadmium. — a. 2CdCy.Cn*Cy =:^ Cd'CcaC^. — Recently preci- 
tuted cadmic h jdrate diasolvea very slowly in excess of hydrocyanic acid, but qoickly^ 
and with evolution of carbonic acid and cyanogen, on the addition of recently precipi- 
tated cupric carbonate. If the addition of the latter stibslance be discontinued before 
the oxioe of cadmium ia completely dlssolTcd, there renmina a laTender-blue residue, 
which diaaolvea partially fei boiling water (leaving pure oxide of cadminm) and forms 
a liquid, which »i>oa btH-'omes turbid and deposits a viscid milky siibstance, becoming 
crj'atalline as it cools, and apparently coasisting of a mixture of two different salta. Bat 
if the addition of carbonate of copper be continued till the eadmic oxide \a complett-ly 
diivsolved, a Liquid is obtained which ia colourless at in^t, bnt afterwards a^unies a 
jturple-red colour, gradually in the cold, more quickly at 20** to 25^ C*. and after being 
concentrated at lOt)^, soon deposits crystals of a dingy brown -red colour. The latter 
compound is spanoi^y soLnble io cold water. From the eolation in a small quantity 
of boiling water, it seoormtea in the form of a red tenadoos mass, whicii gradually 
solidifies to a net^wors of cr3rBtati ; but when reciystallised ftora. a lam quantity' of 
boiling water, it forms shining^ rose-oolonred, oblique rhombic prisms, wnieh arc per- 
manent in the air, and are not decomposed at 150^, but at higher temperatures become 
opaque, fuse^ and quickly decompose. (Schuler, Ann. Ch. tbarm. Ijcxxvii 48.) 

b, 2CdCy.CuCy = Cd'CuCy', — When cadmic hydrate and eupric hydrate are dis- 
solved together in hydrocyanic acid, and the colonrleaa solution lyft to evaporate in 
the air, colourless, shining, obliqut*, rhombic prisms are obtained, which at 14H)^ C. 
ffire off 18*4 per cent, of their weight, and crumble to a fine mealy powder. Tlic salt 
18 readily decomposed by acids. Both this and the preceding have a decided aikjiline 
reaction and a peculiar metallic taste, leaving an irritating sensatioii in the throat 
(Schiller). 

Cyanide of cadmium forms Beveral other double aalta: 

The ftrrou^ if ait is a yellow i>redpitate, obtained by mixing ferrotis sulphate with 
cyanide of cadmium ana potasfiium. It turns green when exposed to the air. The 
Itad-salt, CdPb'Cy* » CdCy.2PbCy, is a white precipitate, obt^iincd in like manner 
with acetate of lead and the potftsaiuia-salt* It is decomposed by washing. The 
tnercuru-galt, 2Cd€.y.3H^"Cy^ obtained by dissolving cadmic hydrate and nierctiric 
oxide in hydrocj'anic acid, forms white, opaque, rectangular prisma, easily soluble in 
water and permanent in the air (Scbiiler), The nickd-i/alt is a white precipitate, 
soluble in exceits of cyanide of cadmium and potassium, insoluble in bcuIb. The 
potasttvmsaitt CdKCV*, is obtained m shining regular octahedrons, anhydrous and 
permanent in the aiTi by evaporating a mixture of acetiite of cadmium and cyanide of 
potasaiiun. Weak acids separate pruasie add fifom it, Sulpbydric acid precipitates 
ail the cadmium. The ttiltftr-sali is a white precipitate, likewise soluble in saatem of 
cyanide of cadmium and potassium^ 

CTAJmiB or CJkXaClWtSt Obtained in aqueous solutioD by saturating 
aqueous prussic acid with slaked lime, filtering, and adding more prussic acid to the 
filtrate till it no longer precipitates magnesium-salts. It is decomposed by boiling, 
also by carbonic a<*id, C. Schtik prepares it in the same manner aa the barium-salt^ 
and finds that it cr)'srallis<^« ui cubes. 

CTAJTIHB or caKTOBC Cyanide of potassium forms with cenms saltsi, a 
white gumoiy precipitjite, which, however, quickly gives off hydrocyanic add, and ii 
ConTcrted into cerous hydrate, (Berenger, Ann. CL Pharm. xlii. 139.) 

CTAMtS^m or Cl!irr&. CH^.Cy. (SeoL 840.) 

CTAVSkSS or CMMOmxuws* ChromouM Cyanide^ CrCy, is obtained on 
mixing a solution of chromous chloride in boiled water with a solution of cyamde of 



M 



CYANIDES OF COBALT. 205 

potassium, as a white precipitate, soluble in excess of the alkaline cyanide ; but it 
oxidises yery quicklj during washing, and is converted into a mixture of chromic 
ejanide and chiomie oxide. 

Chromic Cyanide, Cr^Cy*, is precipitated on mixing a chromic salt with cyanide 
of potassiuuL If an aqueous solution of chromic chloride be added to a solution of 
<nranide of potassium, a light bluish grey precipitate is formed, insoluble in excess of 
the alkaline (^anide ; but when the latter is added, drop by drop, to a solution of 
chromic chloride, the first portions of the precipitate redissolve in excess of the 
chromic salt ; an excess of cyanide of potassium renders the precipitate persistent in 
tiie cold, but soluble on heating ; and to render the precipitate quite permanent, a still 
larger quantity of cyanide of potassium must be added. 

When a mixture of chromic hydrate, potash, and hydrocyanic acid is exposed to the 
air, it turns brown and yields crystals of a double cyanide of chromium and potassium, 
analogous in com^ition to ferricyanide of potassium, and capable of forming by 
doable decomposition salts of corresponding constitution, called chromicyanides. 

Chromicyanide of Cobalt is a blue precipitate. 

Chrcmicyanide of Hydrogen^ or Hydrochromicyanic acid^ 3HCy.Cr*Cy*, is obtained 
in crystals b^ decomposing the silver-salt suspended in water with sulphydric acid, 
and evaporating the filtrate in vacuo. 

ChroTfucyaniie of Letui is a white precipitate while moist, greyish when dry. 

Chromicyanide of PotasnuMj SKCy.Cr^Cy*, forms cryst^ils isomorphous with the 
ferricyanide, and exhibiting the faces ooP . f P. — P . [Poo]. The solution gives 
a white precipitate with zinc-*alU^ brick-red with ferrous salts, white with nitrate of 
silver ; it does not precipitate nitrate of lead or ferric salts. 



CTiUnDB OT CZVVAMYX. C^H'NO = C»H'O.Cy (i 990). 

CTAVZBBS or COBAZiT. Protocyanide of Cobalt^ or Cobaltous 
Cyanide, is obtained by adding cyanide of potassium to a cobaltous salt, as a flesh- 
eoloored or light cinnamon-coloured precipitate. It dissolves in excess of the alkaline 
cyanide ; and the solution exposed to the air is converted into a double cyanide of 
cobalt and potassium, analogous in composition to the ferricyanides, and yielding by 
double decomposition a series of salts called Cobalti cyanides, whose composition 

is expressed by the general formula SMCy.Co'Cy* « .^,y« 5 Cy«; if we suppose these 

salts to contain cobalticum, co » } Co, the formula may be reduced to MCy.coCy ib 



Z\oy'- 



The Sesquieyanide of Cobalt, supposed to exist in these salts, is not known in the 
separate state. 

Cobalticyanide of Ammonium, (NH«)*Co*(>^ + i aq. = 3NH*Cy.Co*Cy + J aq,, 
obtained by neutralising hydrocobalticyanic acid with ammonia, crystallises in rhombic 
tablets, very soluble in water, sparingly soluble in alcohol, and decomposing at 230° C. 

Cobalticyanide of Barium, Ba*Co*Cy* +12 aq., obtained by dissolving carbonate of 
barium in hydrocobalticyanic acid, crystallises in colourless prisms, very soluble in 
water, insoluble in alcohol, efflorescing in warm air, and more quickly at 100° C. 

Cobalticyanide of Cadmium is obtained as a brown precipitate, which after- 
wards turns white. It is soluble in acids and in excess of cobalticyanide of potassium. 

Cobalticyanide of Cobalt, Co*Cy« - 3CoCy.Co«Cy*, or^lCy*, analogous in 
composition to TumbulTs blue (see Cyanides of Ibon), is prepared as follows : 

1. Cobaltimnide of potassium forms with sidphate of cobalt, a light red precipitate, 
which may be completely freed from the potassium-salt by washing. The same 
precipitate is formed by adding hydrocobalticyanic acid to cobalt-salts.— 2. When 
hydrocobalticyanic acid in the dry state is heated with strong sulphuric acid, and 
water added before the decomposition is complete (vid. infX cobalticyanide of cobalt is 
precipitated in the form of a pale red amorphous body. The product obtained by (1) 
contains 7 at water, part of which it loses at 100° C, turning blue at the same time, 
and the rest at a higher temperature. The product obtained bv (2) contains only 
6 at water ; when heated it gives off water, and turns blue. Cobalticyanide of cobalt 
is perfectly insoluble in water. Caustic potash decomposes it, separating hydrated 
protoxide of cobalt Ammonia dissolves it partially, forming a reddish solution, and 
separating a green powder. Mercuric oxide nas no action upon it The product (2) 
n-hists the action even of strong nitric and hydrochloric acids; from (1), however, 
strong acids extract water and turn it blue. The anhydrous compound has a deep 
blue colour ; in contact with moist air, it rapidly absorbs water ana turns red ; when 
water is ponred upon it^ ^mbination takes place, attended with great evolution of 
(Zwenger, / 



hmL (Zwenger, Ann. Ch. Pharm. Ixii 172.) 



206 



CYANIDES OF COBALT, 



Cobaltiet/anid« 0/ Copper^ SCuCy.Co'Cy*. — ^The dense eky-blufl precipitiito 
whicli eobulticyatiide of potoflaium forma witli eupric ealts (G m elin). It ia also formed 
by prcci pi luting cupric raits irith hydrocobalticjaiiic acid. It is inBoluble in water 
and in acids ; warm potash-lej separates capric oxide from it ; ammonia dissolves it 
completely, forming a blue ftolution. (Zwonger, Ann* Cli. Pharm, Irii. 170,) 

Ammonij>'€4)baIticyanidi! of Copper, 2NH'.Cii*Co*Cy*,^Crystalli8e» by slow eTaponi- 
tion from the ammonincal solution of cobalticyanide of copper, in email, whining, txtnta- 
colouped^ four-sidi^ priami, with octagonal summits j aJcohol addni to the ammo- 
niacal iioltitioti thixiws down the compound as a blue, slightly crystaUiae powder of 
much lighter coloor. The crystala are inBolublo in water ; when cxpoBcd to th^ air or 
heated to 100*^ C. thoy giTe 0IT ammonia, li«;ome opaque, and aaaume a lighter colour. 
Acids withdraw the ammonia completely, leaving cobalticyanide of copper in the form 
of a li^ht blue powd**r. When the compound is heated with potftsh^ ammonia is given 
oS^ cupric oxide Beparated^ and cobalticyanide of potas.sium left in sol ution. (Z w e n g c r, 
he, eii.) 

Cobalticyanide of Hydrogen^ or Eydroeohalticyanie acid, H'Co'Cy^« 
3lICy.Co*CV. — Obtained ( 1. ) by pa.«isizigfulphiii«f ted hydrogen through water in which 
cobtifticyamdeof lead [or of copper] is difiused^ than ifilteriug and evaporating to the crys- 
talline point.— 2. By decomposing the conccntratad aqueous solutioa of cobalticyanide 
of pot4is8ium.with a alight excess of sulphuric or nitric afiid, adding absolute alcohol^ and 
rocrystAllising the mass which remains after evaporation, Crystalliaea in deLLqiif*«c<5nt^ 
ci:»lonrleB«, transparent neediest having a sfst^ngly acid taste. When heated above 
100^ 0, it first gives oif water, then hydrocyanic acid^ hydrocyanato of ammonia, and 
carbonate of ammonia, and at 2fi0*^ C. leaves a blue powder, which at a higher tempera* 
ture is converted into black carbide of cobalts The aqueous solution sufFera scarcely 
any decomposition by boihng. This acid decomposes carbonates and dissolves iron and 
line, with cTolution of hydrogen. It dissolves in alcohol, but is insoluble in anhydrouj? 
ether ; it is not decomposed by hydrochloric acid, fuming nitric acid^ or aqua-regia. 
When hcat-ed with oil of vitriol, it is resolved into carbonic oxide, carbonic aDhydridc, 
snlphm^ous anhydride, sulphate of ftmmomum, and salphato of cobalt ; the a^^ldition 
of water before compiete decomposition^ gives rie& to the separation of red cobalti' 
cyanide of cobalt, which, when heated, gives oft' water and turns blue, (Zwenger, 
Ann. Ch, Pharm. brii, 147*) 

Cobalticyanide of Iro^ (ferrosum) is a white precipitate obtained with ferrous 
»ulf>hate and cobalticyanide of potassium. Ferric euts giTe no precipitate with the 
latter. (Zwenger*) 

Cohahicyanide of Lead, Pb'Co'Cy* + 2 aq,, obtained by decomposing carl«3natfl 
of lead with hydrocobalti cyanic acid, crystallises in nacreous scales^ veiy soluble in 
water, insoluble in alcohol Ammonia added to the aq^ueous solution throws down 
a basic salt, 2Pb'Co=Cy*.PbH0.3Pb^. (Z we n g or.) 

Cobalticyanide of Manganese is a white precipitate. 

Cobalticyanide of Mcrcurosum is a white precipitate, Mffreurto salts are 
not precipitated \j cobalticyiinide of potassium. 

Ctibaitioyanide of Nickel, Ki'Ck)=Cy*. — Cobalticyanid e of potassiuTO forms with 
sulphate of nickel, a flaky precipitate of a light sky-blue colour (Gmeliu), li^ht-grf f?n 
(F* and E. Rodgers), The precipitate is not attacked by boiling hydj\)chluric acid 
(Liebig). — According to Zwenger, tho precipitate obtained by adding cobalticyanide 
of potajssium to nickel*salts always contains cobalticyanide of potasaiumj which cannot 
be removed by washing. To obtain cobalticyanide of nickel in a state of purity, it is 
neeessaiy to precipitate a nickel-salt ^ith excess of hydrocobalticyanic add* The pre- 
cipitate thus obtained is gelatinous, of a light blue colour, and when exposed to the 
air» dries up to a transparent, greenish -bine, vitreous mass^ exhibiting a eonehoidal 
fracture. It iB porfectlv insoluble in water and in acids. Pofcaah-lev deeomposes it, 
separating hydnited oxido of nickel, but ammonia dissolves it compiotely. Dried at 
100° C, it contains 6 at. water. At a higher temperature, it gives off its water and 
turns g^y ; but the anhydrous compound, when exposed to tho air, quickly abf^nrbs 
a quantity of water equal to that which it has lost, and resumes its originsl colour, 
(Zwenger, Ann. Ch. Pharm. Ixii. 173.) 

Ammtnut>*cf>btjlticf/anidt' of Nickel. 2NH',Ni'Cb*Cy* + Jaq. — Recently precipitAtcd 
cobalticyanide of nickel dissolves readily in ammonia, forming a bluish solution, which, 
when slowly evaporated, deposits the ammonia-compound in blninh crystalline scales. 
The compound may also be precipitated from tho ammouiaeal aolutian by alcohol ; the 

fjrccipitate is white at first, but when allowed to settle down quietly, it aesumes a 
»luish colour. The precipitate is amorphous, and inHolublo in water. Acids withdraw 
the ammonia, and leave cobalticyanide of nickel in the form of a light blue powder. 
This compound nudergoes no alteration when heated in the air to 10(J<^ C. ; at a higher 
temperature it takes fire, and bums away with strong intumescence. (Zwenger, he. 
cit.) 



i 



CYANIDES OF COPPER. 207 

Cohaltieyanids of Pot as 8 turn, K«Co*Cy« = 3KCy.Co«Cy«.— Obtained : 1. By 
treatiiig protocyanide of cobalt with aqueous cyanide of potassium, or by gently heating 
carbonate of cobalt with potash and hydrocyanic acid. If the action takes place in a 
dose Teasel, it is attended with evolution of hydrogen (Gmelin) : 

4KCy + 2Co(^ + H«0 « K«Co«Cy + KHO + H 
C6«0 + 3KH0 + 6HCy« K«Co«Cy« + 4H«0 + H; 

in contact with the air, howeyer, no evolution of hydrogen takes place, but oxygen is 
absorbed. The product is purified by recrystallisation. If the crystals are contami- 
nated with cyanide or carbonate of potassium, these salts must be decomposed with 
aoetie acid, and the solution precipitated by alcoboL 

Cobalticyanide of potassium forms anhydrous flattened prisms, transparent, slightly 
yellow, and isomoipnous with ferrocyanide of potassium. Ordinazy combination 
+ P . — P . ooPoo . [ »PooJ, the face — P sometimes predominating over + P. Twin 
erystals likewise occur. The salt is yeiy soluble in water, insoluble in alcohoL When 
heated it melts to a daik olive-green mass, and if not in contact with the air, eives off 
nitrogen and cyanogen, ultimately leaving cyanide of potassium and carbide of cobalt. 
Snlphurie or nitric acid, added in excess to a strong solution of the salt, throws down 
eobalticyanide of hydro^. The dry salt heated with strong sulphuric acid, is com- 
pletely decomposed, giving off a mixture of carbonic oxide and carbonic anhydride, 
and leaving sulphate of cobalt mixed with sulphate of ammonium. 

Cobalticyanide of 8ilv^, Ag*Co'Cy« « 3AgCy.Co*Cy*, obtained by preci- 
pitating nitn^ of silver with cobalticyanide of potassium, is a white curdy mass, anhy- 
drooa, insoluble in water and in acids, not altered by light 

It dissolves in ammonia, and the solution yields by evaporation colourless prisms of 
mmmamo-oobaliicyanide of silver^ NH".AgH)o*Cy* + J aq., or cobalticyanide of silver 



and 



argentammonium, CoKJy* |^^2a|^§| + 4*^' 



Cobalticyanide of Sodium, NaK/O^Cy* + 2aq., prepared by saturating hydro- 
cobalticyanie acid with carbonate of sodium, forms colourless transparent neecues, very 
soluble m boiling water. 

Cobalticyanide of Tin {etannous)^ is a white precipitate. 

Cobalticyanide of Zinc is a white precipitate. 

OTJLKTDWB OV COPVBX* Cyanogen unites with copper in three different 
proportions, forming the cupric, cuprous, and cuproso-cupric cyanides, the last of whidi 
may be regarded as a compound of the other two. 

Pbotoctanidb op Coppbb or Cupbic Cyanide, CuCy, is known only in 
the hydrated state, and is obtained as a brown-yeUow precipitate by adding cyanide 
of potassium, not in excess, to cold solutions of cupric salts (Scheele), or hydrocyanic 
add to solution of cupric acetate (Pagenstecncr). It is veiy imstable, decom- 
posing spontaneously, even at ordinary temperatures, into cyanogen and hydrated 
cuproso-cupric cyanide ; hence its properties are but little known. 

According to Buignet (J. Pharm. [3] xxxv. 168), cupric cyanide is produced only 
when cupric sulphate is added to excess of cyanide of potassium, as a yellow-green 
precipitate which subsequently redissolvos ; if, on the contrary, the cyanide of potas- 
sium is added to excess of the cupric salt, cyanogen is evolved and cuprous cyanide is 
formed. 

Cuprioo-cyanide of Potassium, KCy.CuCy, separates on evaporation from the above- 
mentioned solution of cupric cyanide in cyanide of potassium, in rhombohedral crystals. 
It di»olvee in | of its weight of water at 16° C, and in J pt at the boiling heat. The 
saturated solution boils at about 120^. The solution, which is colourless, is pre- 
cipitated by fixed alksJis and coloured by ammonia (Buignet). 

Hbmxotanidb of Coppbb, or Cupbotjs Cyanidb, Cu'Cy, or CcuCy. 
Dieyanide of Copper, — ^This compound is obtained in the form of a white hydrated 
powder by adding cyanide of potassium or hydrocyanic acid to a solution of hemi- 
chloride of copper in hydrochloric acid, or to a solution of cupric sulphate mixed 
with sulphurous acid. The precipitate is soluble in aqueous ammonia, dilute adds, 
and alkaline cyanides. It melts when heated, giving off water, and leaving a light 
brown-red tumefied mass. 

Cuprous cyanide may be obtained in anhydrous crystals, possessing considerable 
lustre, by suspendinff in water the compound of cuprous cyanide and cyanide of lead, 
and passing sulphySric add gas into the liauid, taking care to avoid an excess. 
Hydrocuprocyanic acid (cyanide of cuprosum and hydrogen) appears then to be formed, 
and if the filtered liquid be left to evaporate spontaneously, it gives off hydrocyanic 
add and deposits cuprous cyanide ("Wohler, Ann. Ch. Pharm. Ixxviii. 370). — Accord- 
ing to l>aaber {ibid, body. 216), the crystals belong to the monoclinic system, the 



208 



CYANIDES OF COPPER. 



dcaninaiit ttem being coP . »Paa . oP» Indiiuition of ooP : woP m the plane of the 
idinodiagoiial and principiil axis = 68*=' 32' j oP : «P = 70*^ 16' ; oP : qoPod » 
£3^ 10. Ratio of orthodLigoiud to clinodkgODal » 0'£4S3 : 1. CHea&Tage peffect^ 
parallel to oF, 

CtiprouB cyanide uoitcs with the cyamded of the alkali-metak, fonning coloiiHess 
Bults, irhieb may be called cuproao-cjiinides, from which adds, added to tlieir 
Bolu^ons, precipitate cuptotis cjauide in thick white flakee with erolndoii of hydro- 
cyanic acid, 

Citprcxoci/anide of Ammonium^ NH^CuKJy*, op KH*Cy. CciiCy » — ^If in the pwi- 
paration of duunmoniacal cnproso'Caprie cyanide (p. 209), the pa&Bagc of the gas ba 
continued after the needles of the green cyanide hare fomted, theae crystals first re- 
dissolre, aft-er which Uie liquid gradually loses ita colour. When concentrated and left 
to cool slowly, it deposits beautiful^ colourless, prismatic needles of CBprosocyaiiide 
of ammonium. This salt is but sparingly soluble in water, and decomposes when 
continuously boiled therein. At 10 OP C, it gives off cyanide of anxmoiumiii, and at a 
temperature a little above^ is rapidly converted into cnprooa cyanide. (DufaUi Compt. 
rend. xxxvL 1099.) 

Cuproaoc^anide of Barium. — ^Wlien aqueous hydrocyanic add is poured upon a 
mixture of carbonate of copper and hydrate of barium^ the whole dissolves with brisk 
efiTervescence, forming a crimiKJU solution, which leases a colourleas residue when 
er&pomted. Water poured upon the residue dis«oh'e« out the coloufless double cyanide, 
learing a residue of carbonate of burium. (M e i 1 1 et,) 

Cupro^ocyanide of BismutK — Cuprosocyanide of potajssiom ct (p. 210) fonns, 
with bismuth 'Salts, a ydlowisb^white precipitate, which dissolvea in acids with cvolu* 
tioQ of hydrocyanic acid* (1 1 1 n e r*) 

Cuprosocyanide of Cadmium* — Cyanide of cadmium and potassium, addtni to 
solution of sulphate of copper, throws down a brownish-white precipitate, with evolution 
of cyanogen gas. ( R a m m e 1 s b e r g. ) 

Cuproiocyanide of Copper^ or Ouproso-cupric Cyanide^ Gn^Cy* = CuCy.CuK?y 

— CcuC*^* — ^^^ brownish-yellow by drat ed cnpric cyanide precipitated by cjanide 

of potiisaium firom cold solutions of cupric salts (p. 207) gradually give© oflF cyanogen, 
and is converted into ctiproso-cupric cyanide (W oh 1 e r, 6 mel i n). The same compound 
is obtained by precipitii ting a cupric salt with ciiprostocyanido of potassium (Ram m els* 
berg). When washed and dried at ordinary temperatures, it fonna siakin-groen 
crystalline grautiles, or transparent prisms, hairing a strong lustre. 

According to Dufau (^Compt. rend, ix^vi 1099), cuprous and cnpric cyanide form 
two cpiiipounds» one having the composition just given, the other contuimng 2 at. 
cuprous to 1 at cupric cyanide. 

a. DuGsa prepares the preceding compound by paaainginto a tolerably dilute solution 
of a cupric Kilt, a solution equally dilute of cyanide of fiotassium or hydrocyanic acid, 
in such proportion as to leave a considerable quanti^of the copper^salt undecomposod ; 
— or by passing a stream of hydrocyanic acid vapoor into water in which cupric oxide 
is suapeuded. The precipitate formed is yellow at first, but rapidly becomes greeJif 
and gives off a eou»iderflble quantity of cyanogen* The green precipitate, which haa 
a crystalline aspect, contains A at* water, so tliat ita fonnula is Cu*Cy* + J aq. 
At 100^ C, it gives off water without deoompodng, but at higher t^mpenitures it gives 
off cyanogun, and is converted into ciiprons cyanide. Aeids sepamte white cuprous 
cyanide from it^ producing at the same time a capric salt, and eliminating hydro- 
cyanic acid. Caustic potash transforms it into cuprocyanide of potassium and cupric 
oxide. Ammonia dissolves it very easily, forming a blueliqnid, which, by B|KintaDeotia 
evaporation deposits beautiful green needles of diammoniacal cuproso-cupric cjanide 
(p* 209). — It dissolves very n.uidily in aquwus cyanide of potassium^ forming a 
colourlsas or slightly bluish liquid, which soon changea to a crj'stalline mass, having a 
nacreous aspect, and consisting of cnproflocyanido of potassium ; its formation ia at* 
tended with evolution of cyanogen. 

h. 2Cu^Cy.€uCy + Jaq* = 0^,^.1? Cy* + J aq.— When a cupric salt ia precipitated 

by a moderately concentrated solution of cyanide of potassium added in rafficient 
quantity to throw down nearly all the ojpper, an amorphouB powder is obtained of an 
olive-yellow colour, and a large quantity of cyanogen is given off: the precipitate has 
the composition above stated. — Botb this compcmnd and the preceding (a) are very 
instable, sometimes decorapoaing spoutaneoualy, sometimes on the sUglitest rise of 
temperature, and, esp^ially in presence of a large excess of hydrocyanic acid, giving 
off cyanogen, and leaving cuproas cyanide. (Dufao.) 

Ammamacal Cuproio-cupric Cyanide, NB**Cu^y.CaC?y. -I- J aq. -^^^f Cy*-*- W 



CYANIDES OF COPPER. 209 

— ^When a solution of cyanide of ammonium is mixed with a cupric salt, a consider- 
able quantity of inranogen is disengaged, and a bluish-green precipitate is formed 
eontaining ammonia, and having the composition just stated. — Bluish green amor- 
phous powder, slightly soluble in cold wat«r, to which it imparts a faint blue colour ; 
when boiled in water, it gives off ammonia and is resolved into cuprocyanide of am- 
monium, which remains in solution, and cuprous cyanide, which is precipitated. — The 
cuprous cyanide obtained in this and in certain similar reactions has more or less 
of a brown colour, but is identical in composition with the white cyanide. The com- 
pound is permanent in the air at ordinary temperatures, but gives off water and 
anmonia at lOO^C. ; a heat somewhat greater converts it rapidly into cuprous cyanide. 
(Dufau.) 

DiammorUacal Cuproso-cupric Cyanide, 2NH».Cu«Cy.CuCy.=^^^lCy«.— 1. The 

preceding compound dissolves readily in ammonia, forming a sky-blue liquid, which by 
spontaneous eTaporation deposits beautiful green needles, having the composition just 
stated. — 2. A more convenient method of obtaining this compound is to pass a stream of 
hydrocyanic acid vapour into ammonia containing cupric oxide in suspension. The oxide 
of copper dissolves at first under the influence of the hydrocyanic acid ; but, after a while, 
small brilliant green needles appear in the liquid, and increase rapidly in quantity ; the 
(Operation is then to be stopped, and the liquid left to cool, whereupon it deposits 
another crop of the green needles. — 3. This salt is also formed by dissolving cuprous 
cyanide in ammonia. The solution remains colourless if protected from the air, but, if 
oxygen has access to it, in ever so small a quantity, it rapidly turns blue, and when 
evaporated, deposits the green needles of the diammoniacal salt. — Diammoniacal 
euproflocupric cyanide forms beautiful green prismatic needles, having u metallic 
lustre ; it is unalterable in the air, insoluble in water, and exhibits with various 
reagents the same actions as cuprosocupric cyanide and the monammoniacal com- 
pound. (Dufau.) 

Triamnumiaeal Cuproso-cupric Cyanide, 3NH».Cu»Cy.CuCy =^.^^J^^^ I Cy«.— The 

diammoniacal compound dissolves readily in warm aqueous ammonia ; ana if the am- 
monia be constantly kept in excess by passing a stream of ammoniacal gas into the 
liquid, the solution, when afterwards le^ to cool, deposits), either prismatic needles or 
ciystalline plates of a fine blue colour. — ^This salt, when exposed to the air, gives off 
ammonia and turns green. It may also be prepared from cuprosocupric cyanide, or 
the monammoniacal compound. (Bufau.) 

NH«Cu % 

Diammoniacal J)ieuproi(heuprio Cyanide, 2NH*.CuCy.2Cu«Cy=NH»Ccuf Cy«.— 

Ccu) 
When an ammoniacal solution of cupric oxide is pwured into aqueous hydrocyanic 
acid, till the odour of ammonia decidedly predominates, the slightly yellow liquid 
then heated to the boiling point, the heat kept up, and the gradual addition of the 
ammoniacal copper-solution continued till its dark blue colour no longer disappears, 
micaceous crystalline laminae make their appearance after a while. If the liquid be 
then filtered, it yields, on cooling, green rectangular laminae of remarkable lustre. 
Ther have a composition denoted by the preceding formula together with 1 at. water. 
On heating them with equal volumes of solution of caustic ammonia and carbonate of 
ammonium not too dilute, a blue solution \s obtained, which, after boiling for an hour, 
deposits shining blue laminsa of the anhydroas compound. The green laminae also 
torn blue when treated with the' fixed alkalis or their carbonates, even in the cold. 

The compound is quite insoluble in cold water, and is decomposed by boiling water, 
with formation of a brown substance. Dilute acids separate from it white cuprous 
cyanide, which ^Ussolves on boiling, with evolution of hydrocyanic acid. (Hilken- 
kamp, Ann. Ch. Pharm. xcviii 218.) 

Honthiers ^J. Pharm. [3] xi 257), by precipitating cupric sulphate with cyanide 
of c upr o enm ana ammonium, obtained a yellow precipitate, to which he assigned the 
formula NB^.CuCy.2Cu*CyM0. 

Cupro9oeyanide of Iron, — a. Cuprosocyanide of potassium, a, forms, with ferric 
salts, a greenish yellow precipitate, from which acids dissolve out cuprous cyanide, leav- 
ing a residue of protocyanide of iron (I ttncr). The precipitate is white, but turns 
yellow when exposed to the air, the surface becoming yellowish green (Rammols- 
berg). — b, Cuprosocyanide of potassium c forms a yellow precipitate, which turns 
greenish on exposure to the air (Rammelsberg); according to F. & £. Hodgers, 
the precipitate la white. With ferrous sulphate free from ferric oxide, no precipitate is 
formed (Omelin). For the other double cyanides of copper and iron, see Ctanidbs 

OFlaOH. 

Vol. II. P 



210 



CYANIDES OF COPPER 



Cuprosocyanidt of Lead. — a. The potajasium -stilt forma, with lead-salt;), a 
whitinh g^Pfen precipitate (white, according to RammelBborg), which diHsolv^s in 
mncLt with eTolution of hydrocyanic acid (I ttD er). — b. The copper-salt b precipitates 
leud-eolts io fine* white, curdy flakes. (Gmeli©*) 

Cupros&cyanide of Ma nqanes e*— ^, Cuprosocy jm ide of potasviam a form a wit h 
mftnganouB salts a yellowish white precipitate, which disikolTes m adds with evolutioa 
of hydrcKTjramc acid (Itttier).^-6. The potaaaiam-aalt c? forms a white precipitate 
with manganoua &alt«. (Gmelin.) 

Cuprosocyanide of Poiastiuifu — Cuprotui cyanido forma three compounds 
with cyanide of potaasiiam. 

a. KCy.Ctt^Cy — --, f Cyl^-This salt was diacoTered by Ittaer, and farther inves- 

tigatcd Ify Leopold GmoKn and RammclBb'erg. 

Frqyartition, — ^1. Cnpric hydrate or cuproso-cupnc cyanide, is dissolyed in aqueoii» 
cyanide of potassium, and the filtrate eTaponitM to the <iryst^lii}iiig point (IttoerK 
Monthii^rs poors excess of potash on hydrated cnpric oxide, and adtls hytlrocyiinic 
acid till the hydrate is dissolTed, and the liquid hccomea quite co1ourle«5. To 
obtain a perfectly white salt, he avoids the application of heat, — 2. Oaprous cyanide 
is precipitated by cyanide of potOififiinm from the solution of cuprous chloride in hydro* 
chloric acid^ and potasli added to the liquid till it reddeua turmeric, then hj'drocyanic 
icid till its odour becomes permanent, then pot;ii«h again, and bo on alternately ; the 
residual white powder ia then dissoh^etl by adding a large qmmtity of wat-er and 
boiling, and the liquid is eTaporated and cooled. The salt a crystaUiaes out first, after- 
ward!* the more Bolnble salt b (GiDelin).— 3. This compound may also bo obtained 
by adding cyanide of potassium to tho aqueonti solution of acetate of copp-er till the 
precipitate which forma at first is rediissolveiL The Bolntion, which is formed with 
evolution of cyanogen, asfinmes at first a purple-red colour, but afterwards on further 
addition of cyanide of potassium and heating, turna yellow (Eammelsberg).^ — The 
solution, whether prepared according to 1, 2, or 3, yields on eyaporatum or oooHngt 
first, a comparatively ainall quantity of the cryBtallisetl s^ilt a, and then, by furthcT 
evjiporation and cotilinisj, a larger quantity of the cryst^^ls c. (Kammelsberg,) 

The salt forms traneparent monoclioic ciystals, exhibiting the faces oP . -i- 2Pao . 
— 2Paa , ooP , — P» [Pco ]. The crystals are often much elongated in the direction 
of the orthodiagonal. Inclination of anP : ooP in thecUnoniiagonal section := 94^ 30' ; 
oP : -P = 13P 54' I oP : ^2Pcc «= 126^ 13'; oP r [Pa3 ] = 136** 46', Inclina- 
tion of dinodiagonal to principal axis ^77° 8' (R am m els berg, Pogg. Ann. cvi. 491). 
The crystals are pale yellow according to Ittner and Omelinj hut colourless according 
to Bammebberg, who regards tho colouring as incidental; also according to Mcillet 
(J. Phann.[!l] iii, 443) and Monthiers (i^iV/. xi. 266). Tjy^tc bitter and metallic. 

The crj'stitis, when heated, give off a small quantity of wiiter [priibably only hygro- 
scopic], become white and opaque, and affcerwarda fuse to a transiwrent liquid, pale 
blue by transmitted light, but having fine browu-red particles floating in it, which 
impart a brown-red colour to it by reflected light ; no furtiier decomposition ensnes at 
a moderate red heat (GmoUn). Thoae brown-red particles, which separate from 
the originally colourless liquid, consint of very finely divided copper, whence also 
proceeds the blue colour which the liquid afterwards exhibits by transmitted light 
(Rammeleberg). Sidphuretted hydrogen passed throngh the aqueous solution, 
throws down but a small quantity of copper, even after a long time (I ttner, Ram- 
melsberg). Tho strenger acids added in small quantity throw down white 
eaproua cyanide and eliminate hydrocyanic acid (Gmelin). The Siime effect is 
produced by the salts of ferric and stannic oxide, cxcf'pting that the hydrates of these 
oxides are at the sam** time precipitated (Ittner). Mercuric salts throw down 
cuprie [? cnprous] evanide, with formation of cyanide of mercury and a potassium-salt^ 
Alkalis have no action on this coniftound (Ittner.) The crystals dissolve sparingly 
in water, with partial sep:iration of cuprous cyanide* whereby thoy become opaque, 
and afterwards crumble to a white powder. The solution when evaporated first yields 
ciyfftals of the salt a; then of c \ the former is therefore rendered soluble in water 
only through tho medium of the latter. (Bam m el a berg.) 

ITS ) 

k 2KCy.3Cu*Cy = p, ,[Cy*.— Formed by the action of potash on cuprous cyanide. 

(Bammelsborg, Pogs, Ann. Ixiv. 65.) 

c. 3K0y.Cu'Cy»ap f^J*- — Discovered by GmeJin, more minutely examined by 

Riimmeliiberg. Prepared in the same manner as tho salt a. In some eases» the salt a 
crystallisi^ first from tho liquid, and afterwards tho salt A; or, if the quantity of 
cyanide of potafisitim present be considerable, the salt b crj'Htallises out alone. Ac- 
cording to Prince Btigration {J. pr, Chem. xxx. 367), copper dissolves in aqueous 



CYANIDE OF ETHYL, 211 

eyatisde or lienocjftmdo of potassium, and in tliiis reaction tho same salt w produced 
logetlier with free potash, 

Tbii iftlt forma colourless, transparent, rhombic pritinis, truncated oq tlio late rid 
edges, and baTiog ft-aided suramitM (GnieliD). Permant'Dt in the u.ir (Rommel a* 
ha§)i aoquires a bluish whit^ tint aller long keeping (Gmelin). The crystals 
deervpifAte when heat«d, and iit & ti'mpcrature much li«low rednesH they fuse witboiit 
loos tk water, and form a liquid wliich is likewise blue by tramjuiitted, and brown -red 
by reflated light, and does not undurgo any further decompOBition at a raodt^nitc red 
beat ; on cooling, it soUdifies into a mufis coloured reddish white by admixed piirtidrti 
of copper. Small quantities of the stronger acids precipitate euprous cyanide from 
thm mmtixmf and liberate hydrocyanic acid (Gmelin). A dnuhir eSeet ia produced 
t^ §egnc aalts, a precipitate of hydraled ferric oiJde being, howarer, formed at the 
ome time (Hammelsberg). Mereurous nitrate forma a green precipitate (Gmelin). 
The salt diasolTes readOy in water, and its worm concentrated solution takes up a 
eonsderahle quantity of the salt d, bo that, as it cook, crystals of a separate out 
(Baa&melsberg), The EKjlution of the salt e forms a pale yellow precipitate with 
evprie salts (Gmelin, F. & £. Eodgere}. This predpitata should bo CuH!3y^ or 

This salt forms colourless, transparent, raonoclinic prisms, exhibiting 'the faces 
obP . oP . — P , [2Pao], with the inclinations coF : ooP in the clinodiogonal prin- 
cipal section = 102° 32'; oP : »P = I02<= 10'; oP : ^P ^ 142° 69' j oP ; [2Pqo J 
- 130O 67'. 

CuproMo^yanidg of Sodittm,— Formed by precipitating the solntion of the 
c strc sp o n ding burium-salt with an equiruleni quantity of sulphate of sodium. On 
cr aporafing uie filtrate, it remains in the form of small needles permanent in the air. 
(M eiUet» J, Pharm, [3] liL 413,) 

CmproMO'Cyanidc of UmnyL^-ThG potaiaiuni-salt e added to uranic cMorido 
tbfows down a pale yellow powder, (Om e li n.) 

Cu^roMo-eyanide of Zinc. — The potassium-salt a forma with zinc-salts a white 
precipitate, which dissohes in acids with separation of prusaic acid (Ittner), Tbo 
potassium^salt c forms curdy white flakes, (G m e 1 i n. ) 

eYAWTSB Oy CtmSBarrX,, See Gumoiotrilb (p, 283). 

CYAarxss or STBTA. Propionitrile^ Metacctonitrile, Hi/drocyanic eiher^ 
C*ii*N =^ t~li^Cy. — Thia compound was discovered by Peloiize in 1834 (Ann. Ch* 
Pharm. x. 249 X further exam in td byPrankland and Kolbe (ibid. Ixv, 269, 288; 
CbeOL doc, Mem. iii. 386 ; Chem, Soc, Qu. J, i, 60), aud by Diimas, Malaguti and 
LeblmnCt Ado. Ch, Pharm. Ixxiv. 329), It is obtained; 1. By distilling cyanide of 
ptttmmima with ethylsulpbate of potassium or barium, the diBtillate beiag purified by 
wtablllig with water, drring orer chloride of calcium, and rectification ; but the pre- 
paiatioii by this method is attended with the eyolution of an iniolcmble odour, arising 
from, a small quantity of a cyanogen -compound not yet examined, and the purification 
is very diflELcult.-^ 2. By distilling pulverisfid cyanide of potaBsinoi with oxalate of 
ethyl (Lowig). — 3. By diJidlling cyanide of potassium with iodide of ethyl mixed with 
four times its Tolume of alcohol, the condensing apparutua being so arranged that the 
difttilled liquid may continually run back again, tiU, on being tptited. it sliowe no trace 
qI iodine ; the contents of the retort are then AistUled to dryness (Williamson, Phih 
Msg. [4] Ti 205). According to Buck ton and Hofmann (Chem, Soc. Qu. J. is. 260), 
the cyanide of ethyl thus obtained contains a considerable quantity of alcohol, from 
wbieb it eaxmot be freed by fractional distillation ; and to obtain it pure it must first l>o 
ODOTOtsd tuto propionate of potassium by the action of caustic potash (tfid. f>i/.), this 
salt frsed irom alcohol by distillation, then converted into propionic ether (by heating 
it vfth aloobol and sulphuric acid), — the ether converted into propiouamide (N,H^.<J'H*0 
« CH'NO) by the action of ammonia under prt^asiire, — and the propionamide into 
Mvpianitnle (cyanide of ethyl) by the action of phosphoric anhydride. Buckton and 
Hsanaxui, howeyer, regarded tfus as the best method of obtaining pure cyanide of ethyL 

cyanide of ethyl is a colourless liquid, of specific gmvity 078 (Pelouze), 07889 at 
12-60 c. (Franklend and Kolbe). It boils at 82^ C. (Pelouiie), at 88^ (Frank- 
tstid and Kolbe). It has a strong alliseeous odour, and is very poisonous (Pelonse). 
It is very soluble in water (Pelon^e), moderately soluble, but separates on the 
rndditiotk oieommoD. salt (Franklaud and Kolbe). It mixes in all proportions with 

C' *^ ■ and etbcf. 
lids of ethyl cobobated with aqueoiu poiaah is converted into propionate of 
UBif with oTolution of ammonia : 



CTI*N + KHO + HH) = C^H-'KO' + Nm 
f2 



212 CYANIDE OF ETHYLENE — CYANIDES OF GOLD. 



A limOar decomposition ia pn>dneed hj dituie sulphnnc add (I pt itrong add to 3 
pttf. water )^ the proilucts being propionic acid and sulpbate of tunmooium : 

2C'H>N + H'SO* + AWO - 2CH*0' + (NH*)».SOV 

According to E. Meyer (J. pr, Chem. Ixrii 147), snlphate of ethybuniue is like vim 
formed. Heated yd\h fuming stdphurw acid^ it yields disnlphetliolic acid, (7H*S*0** 
tog(»ther witli add ralphate of aimnoniimi and carbonic anhydride (B nekton and 
Hofmann (Cham. See Qn. J. ix. 2d0): 

C»H»N + 3H\S0* ^ C'H'S'-O- + NH*.H:S0* + COV 

Cyanide of fthyl, treated with potaseium at ordinary t«mperatiipes^ is partly decom- 
poaad, yielding cyamd© of pot^asisiiim and fiydride of ethyls and partly polynieriaed into 
i^faiiethine, C'il^N* (Franklandand Kolbe). The formation of bydnde of ethyl in 
tLia reaction mu«t be dne, either to the presence of wat<?r or alcohol in the cyanide of 
ethyl, or to the resolution of the liberated etliyl into hytlride of ethyl and ethylejia 

Cj/aniih of Ethvl and fly«er.— Wlien iodide of ethyl and cyanide of silver in 
equiralent qnantities are healed top^tber to 100^ C. in a itealcd glass tnbe, this com- 
pound is obtained as a riscid oQ^ vhich solidifies in the cjystaUine state on cooling. It 
ts also obtained in fine shimng ciystals on heating to 100*^ C. a mixtnre of iodide of 
ethyl, cyanide of Bilker, and water. It does not yield pore cyanide of ethyl by dry 
distillatioQ, but when diBtilltHl with water, or with potash, it yields a distillat*^ which 
smells of cyanide of ethyl, and when treated with an acid, loses its odour and is con- 
rcTfetl into a salt of ethjlamine. (K Meyer, loc, cit) 

Cyankie of ethyl forms solid oompounds with certain metaUic cMoride^^ riz, 
C»H*N.SbCl*, C"fl»N.AuCl«, C»H*N.PtCl\ 2C*M>^.SnCl*, 2C"H>N,TiCl* i and liquid 
compoundfi with cytmdeof&irbonift, C*H*N.COCl-j and c^^ri^ ofq/anogcn^ C'H*N.Cy CI 
(Henke, Ann* CL Pharm. c\i. 280.) 

crrA3rO>S OF STHTXiSVB* C*n*N'£=(C'H*)'*.Cy*, (MaJEWell Simpson, 
Proc. Eoy, 8oc. i, 674. G cut her, Ann. Ch. Pharm. cxx. 268.)— Produced by the 
aclson of cyanide of potassium on bromide or chloride of ethylene : 
C*H*Br^ + 2KCy ^ (^fl*Cy' + 2KBr. 

A mixture of 1 at» bromide of ethylene and 2 at. cyanide of potassium, with a con- 
Biderablo quantity of alcohol of specific gravity 08 40, is cohobated in the water-l*ath 
till the reaction is complete ; the alcoholic liquid m then decanted and freed from 
alcohol by distUktion ; the semi-fluid residue is filtered at 100*^ C. ; the filtrate i^ 
IreatiMl with a saturated solution of chloride of calcium ; and the cyanide of ethylene^ 
which rises to the surface in the form of a reddish oil, is washed with ether, and 
heated i<yr Home time to 140"^ C, to free it from admixed bromide of ethylene: this 
I trf^iitmeiit does not, however, renderit quite puro (Simpsoo). Gentherprepsi^dthe 
compound from chloride of etbylenei, but the preparation is more difiicult than with 
the Lpiiniide, 

Cyanide of ethylene is» at ordinary t^uiperatiires, a brownish, eomi-solidv ciystalUne 
mass, melting at 60** C* It dissolves readily in water and alcohol, less in eUier. It 
cannot be distilled, but hears a tolerably high temperature without much decomposi- 
tion. With nitric acid it forms a bcwiy which crystallisefl from akohol in long needles. 
H Oil ted with alcoholic potash, it acts similarly to cyanide of ethyl, giving off ammonia, 
and yielding succinate of potassium' 

C=H*Cy* + 2KH0 + 2H=0 = C*H*K:=0* + 2Nm 

CTAirniSJi OF GOXtS. Gold unites with cyanogen m two proxwrtionst form- 
ing the aurouH uud auric cyanides ; the latter, however, is known only in combination. 
Peotoctakide of Golu or Aunous Gtanicb, AuCy, is obtained by heating 
auro<'^yanide of potassium with nitric or hydrochloric acid. It is a lemon^yeUow, ays- 
tall ine powder, whieh, when examined by the microscope, appears to consist of hexa- 
Lgonal plates. It, is insoluble in water, alcohol, and rther, has neither taste nor smell, 
sand in not ftltered by exposure to the air. When heated^ it gives off cranosen and 
I leaves mcfaliic gold. It is not decoinpos*?il by nitric, hydrochlone, or su^hune add, 
e\'en at the boiling heat ; nitro-hydrocbloric acid decomposce it slowly, Stdphydrie 
ficid has no action upon it ; eulpbydrate of iimmonium diflsolTea it to a colotirk'ss liquid, 
irnm which addit throw down sulphide of gold It is soluble in itmmonia. Potash de- 
Cfimpofieit it at the boiling heat^ throwing down metallic gold. It is likewise soluble in 
hyiK>sulphite of sodium. 

Protocytmide of gold dissolpps in the alkaline cyanides, forming double salts called 
aurocyanides, which precipitate the salt* of otW metals, 

AuTdcyanide of Ammon i« w, NH^AuCy^ or NH*Cy.AuCy, is obtained by mixing 
the saturated solutions of sulphate of ammonium and aurocyanide of potassium, pre- 



CYANIDES OF GOLD. 213 

cipitating the s^ph&tc of potjissiiim &nd the excess of fiulplukto of anrniomum inith 
•bflolute alcohol, and leaviugi the fiJtraf^ to crjatailise bj evaporation. It fomia colour- 
lett anhydrous crvstaLi having a strong metallic tast-e. 

The Bolution of protocyaaidio of gold in boiling aqueous ammonia yields, on cooling, 
mj, sbmmg scake, which gire up their ammom'a when heated, or on addition of 
oydrochloric acid. 

Aurocyanide of Potassium, KAnCy*, may bo obtaintjd by dissolving a uron a 
rjanide, auric oiLdo, or fnlminating ^old^ in cjaoide of poUissjum, the solution beiuy 
attended with evolution of cjanogeu in the second cnsfi, and of ummonia in the thinl. 
A oonTement metho^I of preparation ia to dissolve 7 pt«. of gold in nitro- muriatic adil* 
prBd|ntato bj excess of ammonia, and introduce tiie precipitate, wftt^r thorough 
««flhiiig» into a boiling aolutioa of 6 parts of cyanide of potasaiura. The colourleaa 
•olttlioii, if ool too dilute, deposits the aurocyauide in crystals on cooling. Tin* mother* 
liquor jielda by evaporatioii a &esh quantity of the s[dt> but very impiin* ; it in 
trmomted with excess of hydrocyanic acid, aad the residual aurauM cymiiilo ih watibed 
niUi water and dissolved in cyanide of potasfiium (77 pts. cyanide of ^;old to *23 [its. of 
cjmmdo ot potaasium). The crystals are purified by recrystalliisutiou trom boihng 



Aeeoiding to Prince BagratioD ( J. pr> Chcm. xxxL 367 )f metallic gold precipi- 
tated by ferroos sulphate dissolves in aqueous cyanide of pot^sAium^ slowly also In 
feirocyanida of potassium, forming aurocyanide of potusKium. The uctiou requires, 
bowerer, access of air, as shown by Elsnor {^ibid. ixxvii 333), and is attended with 
fbrmatiaii of esostic potash : 

An* 4 ^KCy + ^ 2KAuCy= + K*0. 

Anrocyaiude of potjiflsium forma colourless elongated rhonibo'idal octalicdron** or 
baCTcoiu scales. It is piennuneut tn tho air, moderately soluble ia water, sparingly in 
akohol, insoluble in ether. Heated in a close reaael, it gives off cyanogen gas and 
learoa it roixtnre of gold and cjiinide of potassium. Aqueous aciils slowly decc^nip^se 
Out solution, etimiutiting hydrocyanic acit^ and precipitating aurous cyanide. Boiled 
with hydrochloric acid, it yields al»out 88 per cent, cyanide of potaasium^ together with 
chloride. A similar decompositiou is produced by siibrihuric, nitric^ oxalie^ and tartaric 
acids. Alkaline salphydrates do not decompose it^. The aquc>ous solution mixed with 
memiae ehlonde, yields, without evolution of hydrocynmc acid, a yellow precipitate, 
which iDcrettfles on boiling, and assumes the det^p yellow colour of aurous cyanide : the 
liqidd contains cj^anide of mercuTy and chloride of potaasium, but no gold. 

Aurocyanide of potassium 18 extensively used in electro-gilding. Its aqueous 
fdution, especially when hot^ gilds copper and silver^ even without the aid of a 
voltaic battery^ its place in the solution being supplied by an equivalent quantity of 
tile other metal* 

To obtain the gold which remaiiia* in the solution after it has becD uaed for gilding, 
il ehoiild bo eTapotated to dryness, the residue tinely pulverised and intlnmtely mixed 
with «ti equal weight of litharge, then melted at a strong red hviit, and the Itad 
cxtneted from the button of lead and gold by wann nitric acid; the gold then 
rcinaillii in the fona of a loode, yellowish-brown, spongy moss. (Bottger, J. pr« 
Chtsn. xzxtL 169.) 

The solution of aurocyanide of poLossium forms a white precipitate with W»(^sidts ; 
ydlowiflh-white with tin-mi}tM; white with had-BoltBi white with ff^mnut aalts, 
cbjuiging to blue on addition of nitric acid ; white with nitrate of idlver; with chloride 
of man^nese it forms small cr} Btals. 

Tbioyakidb of Oolt), or A IT BIO Ctanidh. AuCy*» — This compound is ob- 
tained, in the free st^ite, accortling io flimly, by decomposing auricyanide of ^K*tiusiiium 
with any of the »tn>nger aei'lM. It is more probable, however^ as pointed out liy 
L. Gmelin {f{andhtKfk\ yiii. 37), that the subatauce thus se|mrated is auricyanide of 
hvdfogen, HOy.AuCy : 

KAu^'Cy* + na = KCl + UAtt*'Cy* 

Moreover, as ol>8erved by Himly liimself, the compound, when heated, gives off at first, 
not cyanogen, but hydrocyanic acid. 

To preparo aurici/anide of htfdrogcn^ or autifru$$ic aeid^ an aqueous sohi- 
tioa of Baricyanide of potast^ium is mixed with excess of nitrate of silver; the liquifl, 
tODtaining the excess of the «:ilver-@a1tt together with nitrate of potasHitim, is filtered ; 
the precipitate, consiitting of AgCy.AuCy*, is thorougldy washed with water, then dif- 
fiaped in water, and decMmpoe^Hl with frcquetit agitation, and at the ordinary, or at a 
rery slightly elevated temperature (at highi r temperatures a yellow colounug will 
appear, and protocynnide of gold will be fonncdl, by a quantity of hydrochloric atnd. 
Dot ffttfficient to decompose the whole ; aud the filtrate U evaporated -to diyness in 



214 



CYANIDE OF HYDROGEN- 



TActi<J orcr oil of vitriol and lime. — Or, unrieyanid© of potaafliiun i« miied with hy^Jro- 
fluosilicie ncid and erapomted to dryneaa ; the residue exhansted with absolute alcohd ; 
nnd the solution filtered froin the mlieo-fluoride of potassium, and left to erftpoivte 
(Hi inly). The product thiis obtained generally haa a yeUowieh colour, amiiif^ from 
the admiituro of a email (|utmtity of protocyanide ; it must therefore be dis8olT«*d tn 
the smallest possible quanbty of water or alcohol^ and the filtrate left to evaporate in 
thfi liir or in tacuo ; for the application of heat would reproduce protocyajiide of gold. 
(Himly.) 

Auriejiiuidc of hydrogen forms hirgfl ooloforless ]amiD8& and tables, containing 3 at. 
water of ciy,*talli8ation - 2Au'"HCy* -t- 3H*0 (Himly). They fuse at dO<=»a, first 
giving off hydrocyanic acid^ then cyanogen gns, and leaTO carbide of gold, which burns 
readily in the air» and is converted into pure gold. The aqueous eolution, when era- 
pomted over the wat^x-bath, deposits part of the gold in the form of pirotocyanide. A 
boiling aqueous solution of oxalic acid ejcerta no reducing action. Mtrcurou* at mer- 
cttrfc luitiite, heated with the solatiou, throws down DTotocjaiiMle of gold, while 
cyanide of m<?rcary remains in solution. Mtrcuric ckl&ride forms Xko predpitat^ eren 
whcu the solution is heated. Auncyanide of hydrogen does not become moist when 
ejc posed to the iiir, but dissokes in water in crery proportion, and ahnoat as eaeiJy in 
alco hoi and ether. (H i m 1 y, ) 

Auricyanide of Ammontum, (^NH^) Au'^Qy*. — Hydrated auric oxide is added 
to bydrocyanate of ammonia, obtained by distilling ferrocyanido of potassium with sal- 
junmoniao and water, as long as it continues to dissolve ; the eolouHess filtrate in 
heated, which caiisea a huge qnantity of ammonia to escape; the filtrate eraporated 
over the water-hath, during which process it becomes corercd with a rusty yellow film ; 
the dry residue exhatufted with water ; and the filtrate left to c^-aporate till it ciystal- 
lises. The salt forms large, colourless, four and six-sided tables, which give off" 6*06 
per cent of water at 100*^0., and turn reddish-white, yellow at a higher tempermtore} 
and give oflF hydroeyanate of ammrtnia* and when ignited in the air leaT« 68-7 j^ 
ovnt. of pure gold. They dissolve readily in water and alcohol, butara neariy in- 
soluble in other. (Himly, Ann. Ch. rh&rm. xlii. 343.) 

A uric f/ an id e of Potagsium^ KAu*^Cy*.— Formed by eonyerting 7 pts, of gold 
into a solution of the chloride as neutral as possible* and gradually a^ng this liquid 
to a hot coTicentrsted aqueous solution of 8 pts. cyanide of potassium. The eolourlesa 
mixture, as it cools, deposits crj'stols, whii'h may be purifiea by recrystallisation : 

AuCl" + 4KCy = ECy.AuCy» + 3KCL 

(Himly, Ann. CL Pharm. xlii. 340.) A similar process is adopted by Rammelsbt^rg 
(Pogg, Ann. xlii. 133), According to Glaasford and Napier, on the other hand^ this 
mode of preparation yields, not auricyamde. but aurocyanido of potasainm. 

The salt forms large, colourless tables, which, when exposed to the air, effloresce 
quickly and turn inilk-white; in Tacuo (Himly) or at 100° 0. (Rammelsberg), they 
pivn f»ff all their water of crystanisation. The residue then melts to a brown bquid, 
from which part, of the gold Pepawte** out, an evolution of cyanogen taking place at 
the same time (Kammelsberg). The salt, when heated, gives off 2 at. cyanogen, 
and is converted into aurocyanide of patiissium^ KCy.AuCy (Himly). — Chlorine 
exerts a decomposing action only when aided by heat, chloride of cyanogen being then 
formed (Bammelsberg). Adds added to the solution of the salt produce no pre- 
cipitate, but colour it yellow and eliminate hydrocyanic acid (RammelsbergV Mer^ 
onrous nitrate, boiled with the solution, forms a yellowish precipitate (Himly), The 
salt dooH not dissolve in absolute alcohol (Himly)* Its aqueous solution ia the best 
of all materials for galvanic gilding. {Moil let.) 

Aaricf/anide of Silifcr Is a curdy precipitate, formed by mixing the potassliun- 
•alt with nitr;»t/? of silver. It is ?olubhj in ammonia, insoluble in nitnc acid. 

CTAirOIS OV BTDROOrEir. Hydrocifamc or Cjfnnhtfdrie aeid, CNH or 
{CNH) = BCy. Prwsie acid, Acidum horussicum^ BlausMure, Brrh'nfrltlatt*autf,'-TMB 
acid was discovered by Scheele in 1782 (OpfumtlOj ii. 14ft), further examined by 
Berthollet (Mem, rf^ fAcad. d Sc, ds Part^, 1787, p. 141?), Proust (Ann. Cbim. tx. 
18o, 22fi; and Ittuer (Btiirage rur GrschichU dcr Blav^aurf^ 1809). and first ob- 
taincfl in the pure and liquid stat« by Gay-Lussac in 1811 (Ann. Chim. Ltxvii. 
128 ; xcv. 136). It appears, however, to have been known to the E^grptian priests, 
who used it for poisoning the initjut^d who had been guilty of divulging the sacred 
mysteries. (Hoefor, Hiistoir^ dt Ckimie, i. 226.) 

Oreurrencf, — The kernels of bitter almonds, peaches, apricots, plums, cherries, and 
qufrji't'«,— the blossoms of the peach, sloe, and mountain-ash, — the leaves of the pejteh, 
el If Try-laurel, and Portugal laurel,— the young branches of the peach, — the stem-tmrk 
iiS Ui^ Portugal Inunl and mountain-aish, and the root* of the last-named tree, when 




CYANIDE OF HYDROGEN. 215 

soaked in wmter and distilled after a while, yield hjdroojanic add, together with bitter 
almond oiL The joioe of the root of Jatropka Manikot also jields hjdrocjanie acid 
when distilled. But it is onlj in the moister parts of these sabstances that the acid 
exists readj formed ; the greater part is produced daring immersion in water, the 
amygdalin contained in the plants being then resolved, bj the fermentative action of 
the emnlsin, also {Heaent, into glucose, bitter almond oil, and hydrocyanic acid (i. 202X 
the last two sabstanoea passing over in the distillation. 

Formation. — 1. From metallic cyanides, by the action of solphydric, sulphuric or 
hydrochloric add. — 2. In the diy distillation of azodsed bodies, and by the action of 
nitric add on certain organic substances, — in the preparation of nitrous ether for ex- 
ample. It is also found among the products obtain^ by distilling albumin, fibrin, 
casein, or gelatin with sulphuric add and chromate of potassium, or sulphuric add and 
peroxide of manganese. — 3. By the action of heat on formate of ammonium: 
CH(NH«)0»- CNH + 2HK) (Dobereiner, Buchner's Report, xr. 425). —4. By the 
decompodtion of amygdalin (L 222). — 5. By the decomposition of various cyanogen 
compoundi and of fulminates. 

Pirtparation. — L Of the aqueoiu acid. — a. FromkydraUd Fcrrocyanide of pota*" 
num. — ^This salt, which consists of K*FeH;;jy*.3HK), is decomposed when heated above 
100^ C. with sulphuric add and water, in such a manner that half the cyanogen 
passes over in the form of hydrocyanic add, whilst a yellowish-white powder, K*Fe*Cy*, 
IS precipitated, and the reddual liquid contains acid sulphate of potassium. The 
best proportion is 2 at ferrocyanide of potassium to 6 at sulphuric acid ; therefore 
2 . 211*4 Dts. ( — 422*8 pts.) ferrocyanide of potassium, to 6 . 49 (»294 pts.) oil of 
ritriol (diluted with any convenient quantity of water), — therefore nearly 10 pts. of 
the ferrocyanide to 7 pts. oil of vitriol (Everitt, PhiL Mag. [3] vi. 97) : 

2(K*FeK:y«.3H*0) + 6H^0* - 6HCy + K*Fe«Cy« + 6KHS0* + GH-O. 

According \o this calculation, 422*4 pts. ferrocyanide of potassium yield 3 . 27 ( — 81) 
pts. hydiwcyanic acid (in the anhydrous state), or 100 pts. ferrocyanide yield 19*16 
pts. of the add- Gciger obtained by experiment 17*07, and Wackenroder 17*20. — 
A Urger quantity of sulphuric acid does not act farther on the precipitated KFo'Cy", 
and cannot therefore lead to a more abundant evolution of hydrocyanic acid ; on the 
contrary, as it can no longer be taken up by the potash, it decomposes part of the 
liberated hydrocyanic add into ammonia and formic acid, and consequently the hydro- 
cyanic acid which distils over is smaller in quantity and contaminated with formic 
add. It is better indeed to reduce the quantity of sulphuric acid to one-half (3*5 pts. 
oil of vitriol to 10 pts. ferrocyanide of potassium), so that neutral sulphate of potas- 
sium may be formed instead of acid sulphate ; as, however, the neutral sulphate is but 
sparingly soluble, and is therefore deposited in the crystalline form during the distillation, 
it increases the percussive ebullition caused by the white crystalline powder, so that 
drops of the mixture are often thrown up, add mix with the distillate. Hence it is 
good to throw a few clippings of platinum-foil into the mixture. 

The greater part of the hydrocyanic acid goes over in the beginning of \\i^ distilla- 
tion at a temperature somewhat above 100^ C. ; and when the residual liquid attains 
a higher temperature, the water follows, containing but little hydrocyanic acid. A 
good condensing apparatus is therefore necessary; otherwise the hydrocyanic acid, 
which passes over at first, — since its boiling point is not above 27° C, — will for the most 
part escape in vapour together with the air of the apparatus. Water in the receiver 
likewise tends to prevent this loss. It is not necessary to boil the residue down to 
dryness ; it is suffident indeed to distil off from | to J of the liquid, according to the 
quantity of water present 

It is unnecessary to dissolve the ferrocyanide in water l)efore adding the sulphuric 
add. as it readily dissolves in the water as the distilktion goes on. 

The distillatory apparatus must be so arranged as \o prevent any portion of the 
mixture from spiriting over — to contain but little air, inasmuch as the air in escaping 
always carries hydrocyanic acid vapour with it — and to present the greatest possible 
amount of cooling surface. 

If the distillate should become contaminated with sulphate of potassium and prussian 
blue by spirting, it must be carefully rectified over a small quantity of magncvsia, chalk, 
or carbonate of barium, in an apparatus affording ready means of condensation. This, 
however, occadons loss of prussic acid, and the rectified add is much more prone to 
spontaneous decompodtion. 

h. From Cyanide of Potassium. — This salt is sometimes used for the preparation of 
hy<irocyanic add, because it is easily decomposed by dilute acids, even at ordinary 
t<'niperatures. There is, however, greater difficulty in obtaining it in a pur© and definite 
state, and, conse<^uently of determining the exact amount of prussic add that it will yield, 
a point of great importance in the prepiEration of the medicinal add. Ordinary cyanide 



216 



CYANIDE OF HYDHOGEN. 



of potassium, prepared by Liebigfs process (s«c Cyajjidb of Potasshjm), is not well 
jida[)ted for the purposi^ l^^cause it contains a considprable quantity of cyanate and 
ciirbonatfl of potassium, tind the carbonic ax-id eTolved by the deconipotfition of these 
eolt^ prevents, to a considerable extent, the condouBation of thi? hjtirocyanic aeid ; 
mcTOOTer, tUe eyanicacid which also passes oirer is soon resolved into carbonic acid and 
junmonia, and the Utttr induces spontimeonij docomt>osition of the hydrt^cyanict acid. 
It in neecitfttiry, therefore, to use cyanide of potAssium free from cyan a t^, which, nc- 
eordingj to Wyld*»r, may bo prepared by fusing in a eovtred crucible a miiturw of 
dehydrated forrocyanide of potassiun^, burnt tart^ir, and charcoal powdej (p. 217). 
Tlie cooled mass is then lixiiaati*d with cold water^ and the filtered eolation of 
cyan id '3 of potassium is distilled with sulphuric acid. 

Jiy the following method an acid of nearly definite strength may be obtained without 
di^tillution. 

To a SiJution of pt«. tartaric acid in 60 pta* water, contain od in a. well-s^top- 
pcred bottle nearly tilled with it^ 4 pts. of puro cyamdc of potussium olto ad<led; the 
vessel is shaken, frequ^^ntiy dipped into cold water, and then left in the eoM for twelve 
hours; and the aqueous hydrocyanic acid, which contains but a \'cry small quant ity 
of til dm te of potassium, ia poured off from the o^stalliik^ tartrate (Th. Clarku, 
Loud. Mctb Surg. J. vi. 524 ; also J. Chiin* mM. %'tL 0't4). According to calcnlation, 
this acid contains 3'6 per cent, of anhrdrous prnssie acid, 

c. From O^atiide o/Mcrcttiy. — I. Cyanide of mercury ia agitated with iron filings^ 
anlphuric acid, and water in a wi»ll-stoppered bottle, tiJl the Liquid no longer tastes of 
inc^rcury — or better, till a portion of it taken out is no longer blacken eel by sulphu- 
retted liydrogen — the solution then decanted from the iron and mercury into a retort, 
and diet i I led (tjcheele): 

Hg^Cy* 4- Fe» + H»SO^ = Fe'SO* + 2nCy + Hg. 

Aceordingto this equation, 126 pU. cyanide of mercnry require 49 ptsv, or rather inore, 
of oil of vitrioL together with a considorablo quantity of water, and at le^wt 2H pt«. of 
in>ti fHiiigs,^ an excess of iron, howeror, accelfnites the decomposition. If the cyanide 
of mercury be carefnUy weighed,, this method is very well adapted to produce an at id 
of definite strength. The acid distila over at a gentle heat. (Gmehn.) 

2. Sulphydric aoid gas is paKsed through an aqneoua solution of cyanide of mereury 
Hf. long as it is absorbed, ana the solutioD separated by filtration horn the sulphide of 
mercury (Pronftt, Vauquelin): 

Ilg"Cy» + H^S ^ Hg'S + 2Hqy. 

^^luquelin, who employs a polution erf 1 pt. cyanide of mercury in S pta. water, free* 
the solution from excess of sulphuretted hydrogen by agitation with carbonate of leiid, 
till fresh portions of that salt sire no longer browned by it, and filters the liquid again. 
Eut even if these tiltrations Int j)erforrned in a well-covered filter, a eonstiderable 
quantity of prustfiie acid is lost by evaporation, so that this process never yields an acid 
of definite strength ; moreover, the acid thus prepared is apt to be somewhat con- 
taminated with sulphoej'anic aeid and oxide of lead, 

i/. From Cr/anidc of &ih'rr. — 200 pts. of pure cyanide of silver are Bhakeii np with 
240 pts- hjdn:>chh)ric acifl of spt'cific gi-avi ty 11 29^ and, when the decomposition is 
comijletCt the hydrocyjiuic acid is separated irora the chloride of silver by deetintation 
(Everitt, Phil. Mag. [a] vi. UIH ), — This hydrocy&nic add may conlainii small quatttity 
of hyilrocblorie aeid, but htia the advantag;6 of definite strength. 

f. From Ci/amd^ of Liad. — rure cyanide of lead is decomposed by an equiTalent 
quantity of dilute sulphuric acid (Thomson). As, howcTer^ the cyanide of lead ia 
difficult to dr)', the quantity of sidphuric acid required cannot be ejtJictly determined ; 
if too little be used, lead remains in solution. (i>oubcrain» N, J, Pharxn, i. 12 L) 

yi Hydrocyanic lu.'i*! of perfectly definite strength can only bo ohtiuiied by mixing 
weighed quantities of the anhydrous acid and water. Acid of the so-called Scheele'a 
strt^ngth contains 6 per cent, of the anhydrous acid. 

II. Preparation of Anh/drouji Hydroci/anic Acid. — The grc^it volatility and highly 
poisonoufl charactej" of hydrocyanic acid renders this process Tery dangerouiH ; it 
should therefore only be ptTfonned in winter, and with the aid of a freezing mixture. 

It may Ik* prepared dii-ectly by filowly pa^ifting dry sulphydric acid gas through a tube 
filled with dry cyanide of mercury— except at the further end, where there is placed a 
hniall quantity of carbonate of h-ad — and connected with a U-tube surrounded with 
ice and salt. Tlie nnby<lrous acid Ou o passes over and coIJeets in the reeeirer in the 
liquid forni. The passage of the gus must be stopped as soon as the carlionat* of lead 
bqcriii** to bhickcn. (Vauquelin.) 

A better mode of preparation, liowever, is to dohydrato the strong aqueous acid, 
obtained by either of tlie preceding pi-ocesscs, with fiised and pulverised chloride of 



CYANIDE OF IIYDIIOGEN. 



217 



enicium. Traotwein (HepeErt xi 13) distils 15 pta, of ferrocytmidp of fjotassruiri with 

L 9 r>t*. oil of ritriol and 9 pts. water, till 4 or 5 pta. of *itTong iicid huvo passecl over inlo 

, the receiTer, whidi mtjst be surrounded witti ice, or with a mixture of ice nnd aaU ; pjurs 

the acid into n strong bottle provided with & cctod stopper und kept cold by ji freezing 

mixtiunc ; and adds pulverised chloride of eiueium in HmiiU suecessivo portions^ and 

t with frequent ogitatifsn, so that no great development of hent maj take place. The 

k siixtiue, after being left at rest for a whilt?, ftopamtes into two kyore, the lower one 

' cfmmsting at aqucMjun chloride of ealcinm, and the upper of hydrocyanic acid fr<*ed 

trr>iii part of the water. Tho acid is then poured into another bottle, and li^tdn tivatfnl 

with chloride of cakitim ; and this treatnif?nt is eontimwd till fresh qtiantititiiof cLloride 

of calcium added to the acid no longer becomei paHty and eake together, but reiuain 

tmlrerulent By tliis treatmotit, Trautwein obtaioB from 2 to 2| pts, of anhydrous acid. 

Siiiee a considBrable quantity of acid is lost at each dceantution^ and moreover tho 

Tapomr whidi escapes may exert a poisonotia action^ it is better to kave tiie acid iit 

» the fifst bottle and dcuw oSt the solution of chloride of caJeium by a f^iphon. Thix 

sipboD is filled with a satorated solution of chloride of calcium, cloftiid with tho imager 

at the end of tha longer arm, and not opened till thi<^ shorter arm m depn'^sed to I ho 

l0we^ part of tho bottle held in a Bomewbat inclined positioti. As soon as the chloride 

of caJcium Bolution has completely run ovt,, the siphon is again clo^^cd witli tlic fiugcir 

aod taken ouL More chloride of calcium is then introduced, &c. As soon &s n freah 

poition of that subistance no longer becomes pasty, the acid may be decanted into a 

wvU-'OOOIm) bottie containing pulverised chloride of calcium, and finally into a dean 

bottle (Gmelin). Or the acid, after being left for some time in contact with chlorido 

of ealdnm, maybe distilk'd off at the heat of tho water-bath, the bottlo being connected 

by a bent tube with a U'tabe immeraed in ice and salt 

Another method is to pasa the rapour of tho aqueous acid directly over chloride of 
calcium^ which atjBtriu-ts the water. A mixture of 8 pta. ferrocyamde of potaadom, 
3 pta. burnt tartar, mid 1 pt diarcoal is fused in a covereil crucible i the fused mafls 
i!ige«ted with six times itn w^-ight of water in a vessel which can bo closed ; and the 
clear solution decanted from the atKliment of iron and charcoal into a tiibulat^'d retort, 
which ifl connected with a glass tube horizontal in tlie nearer part, bent downwards at 
a certain distance from the retort^ and passing into a U-tube, This U-tube is placed 
witlun a cylinder oootaining cold water, and is filled with chloride of calcium, exe*jpting 
at the end where the vapours enter, and at this end are placed small pieces of tho 
fused mixture aWve mentioned- Tho other end of the U-tube is eonncctt'd by a bent 
tube with the glairs which serveii as a receiver, and is surrounded witli ice, or hotter, 
with a freezing mixture. A cooled mixture of 1 pt. oil of vitriol (the fii.ied niixturo 
vbcee aolatiou is conliiincd in the retort being supposed = 2] and 1 nt. water, is then 
potircd into the retort by smaU portions at a time through a funnel -tube atbipted to 
the tubulua, Tho mixture etarta spontaneously into strong ebullition, so that the sub 
pbniie acid must be added slowly ; and the grtstcr part of the liydroryanic acid distils 
over without the application of heat. Finally^ when all the sulphmc acid has been 
sdded, and the boiling has eease^l, the retort ia heated till tho eontentii begin to boil 
gently ; and the cylinder in which the chloride of calcium tube is iromeraod is emptied 
of cold water, and filled with water at 30^ — 35*^, to volutilido the prussic acid there 
I eoudensed, and cause it to pass over into the re<«iTep(W li b 1 er» B(rzeHv» Lthrk 1816). 
As th^ U-tubc sometim.es oecomes stopped up, WohJcr further recommeuds that the 
Aedc of the retort bo inclined upwards at an angle of about 46^, and an intermediate 
TMBel, containing a small quantity of cldoride of calcium or cyanide of potassium, 
placed between the retort and the U-tul>e. The chloride of calcium tube and the in- 
tiTvening Tessel are inflnersed, from the beginning of tho operation, in water at 30° C.» 
and Uw pruasic add rapour is condensed in a tall narrow v<^sel, surrounded with a 
I miztme of ice and salt ; tha add is then obtained in the form of a cr)'$«tidlin4! mass. 
J V o pfrltigg, —Anhydrous hydrocyanic acid is, at common tempcT^itures, a foIourleMS 
liquid^ of sp, gr. 07068 at 7*^ C, and 69G9 at 18'^ C. (Oay-Lussac); it sc4idiftest 
at 15^ C, in feathery crystals. It boils at 26-5° C. Vapour-density, 9 4 7 by cxperi- 

t(Oaj-LuBSttc), by calculation, — - — = 1 3 -5» referred to hydrogen as unity, 

• 15'6 r 0"0693 = 0*9405 referred to air. It dissolves in water in all proportional, 
Ibtming a eolutiou which is lighter than water, and reddens litmus slightly ; it is aW 
aiisdbie with alcohol 

Tb« Mibydiotis acid or the strong aqueous sobitlnn burns wth a faint violet flame. 
It has A peeuliar odour like that of bitter almondfi. It is exi^essively prnHonoiis^ a 
drop of the anhydrous acid jtrodudng iustnnt death when swtiltowed. The vajwuur 
of the anhydrous or of the hifjjhly coneentnited nqueouh (H'id, is likewise instantly fatal 
when inhaled; tho vapour diluted with air produetii*, when iidialcd in snuJl 4uantity, 
a j*©culiar irritation in the thn^at; in larger quantity, giddiness and hea<baehe. The 




218 



CYANIDE OF HYDROGEN. 



dilute aqueous acid hm a corvling taste, with pmigBnt bitter aftertast^^ ; it is mudi 
lued ia mtMliciiie to allay irritjition* 

I>ecompctgitiuns.—l. Tlio anliyclrous acid quickly undergoes spontaaieoiis doeomposi- 
tion, g:iving oiF aramouia and leaving a brown substance. The aqacous acid undei^es 
thi^ HHinf clocoinpositiijiD* par-f of it boui);^, however^ converted into formats of nmmo* 
niimi ; CNH -t 2H-0 = CH(NH*)0', The decomposition taken place more quickly aa 
the acid i-^ strong<?r; the addition of a Bmallquiintity of another acid renders it more 
pi?nnaneiit ; fllkaliu, on th<* other hand, accelerate the decomposition. Exposure to light 
idso causes the change to take place more quickly ; hence the acid should always bo 
kept in the dark, or in bottles covered with black paper. — 2. The yapoor of hydro* 
cyanic acid passed through a red-hot tube^ is partly resolved into cyanogen and hydro- 
gen gases ; at the same time, however, a small quantity of nitrogen is set free and 
charcoal Bcparat^ — 3. By elr^triciti/. The vapour of hydrocyanic acid is but alowly 
decomposed by the electric spark, with aeparation of a small quantity of carbon. The 
aqueous acid is decomposed by the Toltaic current, hydrogen being evolved at the 
negative pole, while the cyanogen set free at the poBitive pole either remains dissolved 
or unites with the metal which forms the pole.— 4, By oxidation. The anhydrous acid 
tmd its vapour, when Fct on fire, bum in contact with air or oxygen gas, produciug cai^ 
bouic anhydri^dc^ nitrogen, and water. The vapour loixed with oiygen explodes wilh 
great violence on the passage of an eloctHc BparL For complete combustion^ 2 volumes 
of the vapour require 2 J vols, oxygen, and after the explosion, there remain 3 vols, 
of ^ consisting of 2 vols, carbonic anhydride and 1 vol, nitrogen. Hence the com* 
position of the vapour is determineii: for the 2 vols, carbonic anhydride contain 
2 vols, oxygen; conaequctitly, the remaining ^ voL oiygen has been consumed in 
t'ombining with the hyorogon (1 vol) to form water. Hence the 2 vols, hydrocyanic 
vapour contain 1 aL carbon, 1 at. nitrogen, and 1 at. hydrogen. Many mtla/iic oj^d*s 
decouipose hydrocyanic add even at common temperatures ; peroxide of lead forms 
with it^ aecortiing to Liebig, cyanide of lead, water, and cyanogen. — The vapour of t ho 
acid mixed with hydrogen gas is completely absorbed by peroxide of manganese, with- 
out ficparstion of cyanogen (Gay-Lnssae). BaKie inettillic oxides generally ctm- 
vcrt the acid into water and a metallic cyan idt\ — 6. By ch/orinf. The anhydrous 
acid pour^^d into a bottle filled with dry chlorine, and exposed to sunshine, fomas hy- 
di^x'hloric acid and solid chloride of cyanogen. 

In presence of aquexma vapour, but little chloride of cyanogen is formed, the clii«?f 
prcducts of the reaction being sal-ammoniac, carbonic oxide, and carbonic anhydride : 

2CNH -^ Q' + 3H^0 ^ 2Nn*Cl + CO + C0»- 

CMorine gas passed int-o dilute hydrocyanic acid forms hydrocyanate of chloride of 
cyanogen, CNH^l-.CNE (WurtfH Aim. Ch. Pharm. Ixxix. 280). Wlien chlorine gas is 
paraed into a mixture of strong aqueous hydrrK'vauic add and alcohol, till carlxinic acid 
bt»ginf« to cs<-'ape, a crystalline compound, C*ii'NCIt>=', is foiniod. sparingly soluble in 
colli wat^r and in limmoiiia, somewhat more in boiling water, easily in alcohol imd in 
ether. The same compound is formed on passing chlorine into an cdcoholic solution of 
cyanide of nioreury (y. v.) (St en house.) 

6. Bromine decomposes the aqueous acid, forming bromide of cyanogen, 7- lodiM 
doihs not decompose the rapour of hydrocyanic add (Gay-Lussac). With the 
uqneons acid it forms bydriodic acid and Uberat«a cyanogen. (Porrett,) 

8. By adds. Strong hydrocldoric or moderately dilute sulphuric add decompoBcs 
hydmL'yanic acid in a few minutes, even in the cold, and more quickly with aid of heat, 
into fonaie acid and ammonia, CNH + 2H'0 = CH*0' 4- ^HK Hyflrochlorio acid 
acts more quickly than sulphuric acid; the latt^T, if too strongly heat*?d, further 
resolves the formic acid into water and carbonic oxide (Pel ouzo, Ann. Ch. Pharm. 
ii. 84). Small quantities of either of these adds, howovcrp retard the spontaneous 
decomposition of prussic acid, {Qm* vii- 4113.) 

9. The jixrd alkalis, at high temperatures, likewise resolve hydrocyanic add into 
ammonia and formic acid. 

10. Votassium bums when heated in the vapour of hydrocyanic actd, with formation 
of cyimide of pot4iS8ium and evolution of hydrogen. 

Det^viion and ExUmation of Hi/drort/anic acid. — 1. Free hydrocyanic acid, if not 
too dilute or mixed with other odoriferous substances, may be recognised by its 
char»K!teristic ndoitr (p, 217), — 2, On making the solution alkaline with ^^n^A, adding 
a solution of ffrrous milphaie oxidised by exfosure to the air, and then sufBdent 
hydrochloric acid to dissolve the precipitated ferroso-ferric oxide, prussian blue remains 
undissolved if hydrocyanic acid was prcT^unt; otherwise a clear yeJlow-green solutionis 
formed. If the quantity of hydrocyanic acid present is very small, tlie liquid appears clear 
at Brat* but after standing for some time, dsp-nsits dark blue flocks. — 3. The liquid to 



CYANIDE OF HYDROGEN. 219 

lie teitcd is wuxed vith m fev drops of yrfiVw fMlpAidf (pfrtmlpkidt^) c/ammotntrm and 
flvapontcd to dirnes orcr the vater-badi. to conrtrt the hrdroeranic add into sal- 
phocTaoate of amwnnwm. On dissoixing the residue in water and testing with am- 
qncUoride of iron, the hqpad aasnmes the deep biood-red ooloor of feme solpho- 
cjaaatet lliis test, acearding to Taylor (^Ann. Ch. Pharm. Ixv. 263), is capable of 

dktinctly showing the presence <'f :Tr:r-: ol a grain of anhjdious pmssic acid in a Teiy 
difaite liqnid, w hcic a e the prassian bine test will not detect less than ;:^-; of a grain. 

I oU 

—4. Hjdrocjanic acid |;xTea» with nitrcf^ cf sUt^er, a white precipitate of cyanide of 
lilTer, whidi disBolves in ammonia as easily as the chloride, bat is distinguished 
therefrom bj not blackening when exposed to light, and by dissolving in strong nitric 
add at the boiling heat wkh evolntion of carl-onic acid. The precipitated cyanide 
■haken np with dilate hydrochlonc add. emits the charact<^rlstic Oilour of prossic acid. 
— 5. On rendering the hqaid alkaline with pota>h. then adding tulpkait of copper^ and 
JQst suffident hydrochloric add to dissolve the blue predpitate of cupric hvdrate, white 
enproos cyanide remains o&dissolred if the liquid contained prossic acid (Lassaignel 
This reaction is, however, less characteristic than those before mentioned, inasmuch 
as a similar effect is produced by hydriodic acid. 

When liquids containing blood, articles of food, or parts of the animal body, are to be 
examined for pTuasic acid, as in cases of pois«:tning. advantage is taken of the extreme 
volatility of the add, to separate it from the substances which might disguise its 
reactions. A good method of testing is to place a portion of the suspected matter 
on a wmtdb-g^^ cover it with another watch-glass, on the concave surface of which 
is placed a drop of yellow sulphide of ammonium, leave it for ten minutes, then 
evaporate the sulphide of ammonium to dryness at a gentle heat, and moisten the 
residne with a drop of solution of ferric chloride, which, if pruasic acid was present, 
will prodooe the blood-red colour above mentioned. If larger quantities of material 
have to be operated on, it \s best to distil off the acid at the heat of the water>l)ath, 
addulating with tartaric add if the original liquid is alkaline. The distillate may 
then be tested by any of the methods above given. 

Qmantitatire Esthnation. — The strength of aqueous prossic acid cannot be determined 
by its spedfic gravity, the variation from 1-6 to 16 per cent, being only from 0*9979 
to 0-9670. The percentage of real add is therefore determined by one of the follow- 
ing methods : 

1. By Mercuric oxide. To a weighed quantity of the aqueous add, a weighed quantity 
of finely pulverised red oxide of inercury is added, by small portions antl with agita- 
tion, till the last portions added remain undissolved, and the odour of hydrocyanic 
arid is no longer perceptible. The weight of the remaining quantity of mercuric 
oxide deducted from the original weight, gives the weight of the quantity dissolved; 
and since 108 pts. of mercuric oxide require for solution 27 pts. of anhyifrous prussic 
icid, it follows that 4 pts. of mercuric oxide dissolved indicate the presence of 1 pt, of 
anhydrous acid in the liquid under examination (Ure, Quart. J. of Sc. xiii. 321 ; 
also Schw. J. xxxvi. 282). As the cyanide of mercury thus formed is capable of taking 
up more of the mercuric oxide, even at ordinary temperatures, forming indeed, the 
eompoand Hg''O.Hg''Cy*, this method is apt to give too great an amount of hydrocyanic 
add, espedally if the liquid be not kept cool, and the addition of mercuric oxide 
■topped as soon as the odour of hydrocyanic acid has disappeared. Moreover, it must 
first be ascertained that the prussic acid to be examined is free from hydrochloric acid, 
which would likewise dissolve mercuric oxide. In this case, Geoghegan saturates the 
hydrochloric add with carbonate of calcium before adding the mercuric oxide. — Tliis 
method is not i^licable to cherry-laurel water, bitter almond water, &c., because those 
waters contain a vegetable add, probably benzoic add, which likewise dissolves mer- 
curic oxide. (Duflos, Kastn. Arch. xiv. 88.) 

2. nitrate of silver^ mixed with a small quantity of ammonia, such that the liquid 
after predpitation may be rather acid -than alkaline, is dropped into the hydrocyanic 
add, as long as any precipitate of cyanide of silver is produced ; the precipitate is col- 
Iecte<l on a small filter, previously dried at 100° C. and weighed ; and the procij>itato 
and filter are washed and dried together at 100° and weighed. 134 pts. of cyanulo of 
silver indicate 27 pts. of anhydrous prussic acid. The add may also be precipitated 
by a mixture of nitrate of silver and ammonia, and nitric acid then cautiously added 
to the h'quid till a slight add reaction is produced (Duflos). This method is the 
nw>st accurate of all. 

If the liquid contains metallic chlorides, it is acidulated and treated with excess of 
nitrate of silver ; and the mixed precipitate of cyanide and chloride of silver is dried and 
veighed as i^tore^ then treated with dilute hydrochloric add, which converts it wholly 



220 



CYANIDES OF IRIDIUM. 



into chloride of mUreT, md weighed agam. By the oonrereioti of the cymnido of 
silver into chloride, the weight incrcaues by 95 pts. [35'6 (CL) — 26 (Cy.)], to that 
every 9-6 pts. increftse in the weight corresponds to 27 pt*, anhydrous prtifisic add- 

The Bame method ia applicable to the determination of hydrocyanic iwid in pre«eiiee 
of hydrobnnnic or hydnodic acid. From acida not precipitated by nitrate of silrer 
from acid solotions, such oa sulphturic and phosphoric acid, hydrocyanic acid ia eajsily 
neparuted by this reagent. 

3. Voim/utric method, — 1 at- erf anidc of potaamnm forms with 1 at cyanide of sIIvot a 
soluble double cyanide, which i» not decompo»od by excess of alkali. It then, a liquid 
oontaininp hydrc»cyaniC' acid bo mixed with solution of caustic potash till a strong allu- 
lino reiiction ia produced, and then with a standard iolmtion of mtrate of silrer till the 
f liqiud begins to show turbidity, 1 at of silver xmeA will correspond exactly to 2 atw hydro- 
cyanic present in the liquid. If the silver-solution he prepared by dissomng 3*l&0*grm, 
fWd mtrate of silTor in water, and dilating the dolution to 1000 cub. cent, each cub. cent 
of it used will correspond to 1 milligramme of auhytlroiia pnusic add. The presence 
of fonmc or hydrochloric acid has no influence on the resblL Thin method ia quite 
as accurate as the last^ and is applicable to bitter almond jirater and biurel water, as 
well as to luedii'inal prussic acid. Bitter almond water, which is turbid from the pro- 
ficnce of oily ilropst, must first be mixed with three or four times its bulk of water, to 
Tender it clear; otherwise the limit of the reduction will not be seen. (Lie big, Ann. 
Cb. Phann. IxxviL 102; Chem. Soc. Qn. X iv. 219.) 

C&mpoundi of Hydr<^anic acid teiih Metallic Chlorides. 

Hydroq/anati of Antimonic Chloride, SljCl*.3HCy.— When the rapour of anhy- 
drous prusaic add is brought in contact with ptontrtcUondo of antimony heated to 30'^ C., 
this compound is produced in the form of clear definite prisms, which vnlutilise 
liHween 70° and 100'^ C, but at the same time undorjio partial decomposition, evtm in 
an atmosphere of carbonic acid. The compound is deliquescent ; docs not fump in tho 
air; is doeomposed by water, with separation of antimonic acid; and unites with am- 
monia, forming a brown-red pulverulent mass, (Klein^ Ann. Ch. Pharm. Ixxiv. 8G.) 

Hf/drmtfdnaU of FerHc Chiitride^ Fe=Cl'.2HCy.— Sublimed ferric chloride and 
anhydrous prnaaic add unite, with a hissing tioise, and form a brown-red liquid, 
which soon solidifies in the crystalline state. The compound deliquesces in tlio air, 
giTing ojf hydrocyanic acidj melts i^t lOO"^ C; and unites i^ith ammonia, forming a 
greenish black powder* which dissolves in water, with scpai^tion of prussian blue 
and therefore containa protochloride of iron. The compound, when heated, yields 
ferruginous sal-ammoniac, hydrocyanic acid, and pro to-chloride of iron. (Klein^ 
lo€^ ciL) 

HydrocyavaU of Stannic CMiiride, SQCl*.2HCy, — Tetrachloride of tin unites with 
aiiliydrous prussic add, without sensible rise of tempera ture;^ fi^rming a solid eryhtidiine 
body ; if the add in the gaseous state he passed through a tubr^ in which the i^t^oiuic 
chloride is placed, so as to expose a large snrface, the comjwund will be obtaia*'d in 
fine dystala The crystals are oobnrless, refract light strongly, and apjiear to be iiio- 
roorphouji with the corresponding titanium-compound. In a stream of <lry air they 
Tolatilise as quickly as anhydrous pnissic acid, becoming at the same time white and 
opaque. They are decomposed by water and by damp air. Thoy unite mth ammoniocal 
gas, forming a white sul jstance which may be atiblimed. No analysis was made of 
5 1 is compound, on account of its great volatility ; but it appears to be atudogoos to 
tlu* titanium -componnd. (Klein, loc. cit.) 

Bffdrocyanaie of THtanie Chiarid^, TiClMI Cy. — When anhydrous pmesic add ifl 
poured into tetradiloride of titanium, combination takes place, attended with rise of 
temperature and ebullition (on which account the Bubstancos mu«t be cooled to Q^ C. 
before mixing, or the hydrocyanic add must be piiKsed in the furm of gas into the 
titmiic chlonde), and formation of a yellow pulvemlent ma.«<9 ; the exceas of prttssic add 
is then distilled offy and the compound sublimed by careful heating. It is V4*ry vola* 
tile, subliming l>elow 100^ C„ in the form of clear, shining, lemon-yellow ciystals 
(rhombic pynimidM and combinations thereof), which, if rapidly sublimed, unite into 
a coherent mii&s. It fumes slightly in the air; smells strtmgly of hydrocyanic add; 
quickly turns white, and deliquowes to a dear viscid solution. Water djssolres it, 
withnse of tempet^tur^, and ft»rm» a dear solution ; if the quantity of water be small, 
gaseous hydrocyanic acid is given off as the substance dissolves. It is not alteivd by 
sul>limatioji in dilorine gas. When its vai-iour is passed tTiroogh a red-hot glass tube, 
it Lovers the tul>o ydih copper-coloured nifxide of titanium mixed with diaxvoaL 
(Wohler, Afjn. Ch. Phanu. Ixxiii, 226.) 

CTAjmss or Zlixnnnic The only known comiiound of iridium and cya- 
Dogen is the sesquicyanide, wliich forms with basic cyanides a group of salts, tht 



d 



CYANIDES OF IRON. 



221 



iridiocynnidos, 3MCjr.lt*Cy» » M'li^CJy*, unabgoaa to the ferricyunides. They 
hare been chit*fly fftuciicd by C. A. Martiua. (Ann. Ch. Phann* cxvii. 367.) 

Iridiocyanidt of Barium^ Ba*Ir*Cy* 4- 9aq.— To prepare tliis eaJl; platini- 
ferons iridiocyanide of copper, oLtained in the treiitment of platinum-reifiduea by 
Martins' niethod*| ifl digested with bazyta-wat^, the excess of bar>'ta removed by 
earWnic acid, and the filtrate leit to cr)'StulliBe: it then first dopo»ita crystaJa of 
pljiiioocyanide, and nft^^rwardji of iridiocyanido of Imriura, The latter fomjs hard 
tr:uiepar«ut cryet^ts beloDging to the trimetric system^ and efEloreseing in the air to a 
white powdeT still retaining 3 at. wuter. The salt dissolrea easily in water, in insolnble 
in alcohol, and scarcely decomposiblo by ucids. The aqueous solution forms with 
eupric wilta a light blue pn>cipitate, with nicrcurous, ftrrouA^ had^ and zinc salts, white, 
and with/<?rrit' salts a yellow precipitate, 

Iridiocyanide of Hydrogen, H'Ir*Cy*. — Obtoineti by decomposing tho bwriuni 
•alt with sulphuric acid, exhauatinp: with ether, and eTapomting, It forms Bmall whit«i 
crystalline cmsts, has a j^troDg add reaction, decompoaea carbonates, dissolves easily in 
water and in alcohol, with i^lilficulty in ctb<^, and has a nanaeous metallic tast^ Aboye 
SOCP C* it assumes a colour varying from yellow to dark green, and giiri^ oflF pnzssic 
acid. Tho aqueous solubon mixed with hydrochloric acid deposits after a while, groen 
Beaquicy amdtt oi iriilium. (Martins.) 

Iridiocyanide of Potassium^ K*li^Cy*, — ^Preparcd: 1. By gently igniting a 
mixtare of ferroeyonide of potassium and metallic iridium in a glaaa flask, exhaustiiig 
Ui« iDasa with hot water; filtering and evapomting, tho litjuid then depoaiting, first, 
exTBtals of ferrocyanide of potiissinm, and aflerwarda of the iridiocyanide (Wo bier and 
Booth, Pogg. Ann. xxxL 167). — 2v By melting chloriiidiate of azEunoninm with 1 A pts« 
pulverised cyanide of potasaium in a porcelain crucible for 10 or Ifi minutes, dissoMng 
the mass in boiling water, and learing the liquid to cryst^dlise by cooling (Clans, 
Jahresber. d. Chem. 1866, p. 446). — 3. By decomposing tho copper-salt with potash- 
ley» or the barium-salt with sulphate of potassium (Marti us). The salt is anbydrouB, 
insoluble In alcohol, easily aoluble in water, iLnd separates from the aqueous solutiVju 
in large, transparent, colourleas, prismatic twiii-er jstjils belonging t^ the trim etri c systt^m. 
It is not decomposed, even by ignition in a current of chlorine or hydrochloric acid. 
(31 artina.) 

Kaninielsberg*8 analyaii of thia salt agrees best with the formula KTIrCy*, or 
2KCy»IrCy' ; but those of Claua aud of Martina lead to the formula K*lr*Cy' come* 
«ponding with those of the other iridiocyanides. 

CTAVmSft or Zao v. (S c h e e 1 c^ Opiiscid4i^ ii. 148, — 1 1 1 q e r, Beitroffe xiir 
Gtmkiekteder Blam&ure, Freib. Const 1809.— Proust, Ann. Chim, Ix. 185 and 226.^ 
Vanquelin, ibid. v. 113. — Berzelina, Ann. Ch. Phys, [2] xt. 144 and 225; Pogg. 
Ann. XT. 385.— Porrott, PhiL Trans. 1814, p. 627 ; Ann. Phil. xii. 214; xiv. 296.— 
Robiqnet, Ann. Ch. Phys. [2] xiL 276; iriL 196; xHv. 279.— Thomson, Ann. 
PhiL xiL 202; xv. 392; xvi. 217.— Qay-Luaflac, ibid. xlvi. 73- — L. Gmelin, 
Schw. J. xxxir. 326, — ^Pelouze, Ann. Ch. Phys. [2] Ixix. 40. — Kammelsberg, 
Pogg. Ann. xxxviii. 364 ; xlii. 3.^ — Buns en, ifnd. xxxiv. 131 ; xxxtl 464. — ^William- 
son, Ann. Ch. Phann. IviL 226.— Gm. vii 429.— Gerh. L 320.) 

The protoeyanide and gesquicyanide of iron have not been obtained in very 
definite form. On adding cyanide of potassiom to a ferrous salt, a yellowish^red fioc^ 
culcsnt precipitate is formed, consisting essentially of ferrous cyanide, FeCy» but 
always coctaining a certain quantity of cyanide of potassifun, smaller, however, the 

the ifoa-salt is in excess. This precipitate dissolres in excess of cyanide of 

Btitm, and is converted into ferrocyanide of potassium; dilute potaah-ley also con- 
I it into ferrocyanide, with separation of ferrous hydrate : 



3FoCy + 2KH0 = K'PeCy* ^ 2FeH0. 

When exposed to the air, it takes np oxygen and turns blue. (Fresenius, Ann. Ch. 
Pharm. en. 210.) 

Sesqnieyanide of Iron, or Ferric Cyanide, Pe^*, is not known in thesoHd 
Cbfm. Ferricyanide of potassium forms with sesquichloride of iron a dark brown 
liquid, which may be regarded as a mixture of cblondo of potaasimn and acsquicyanide 
of iron: 

K'FeKJy* + Fe'Q* = 3KC1 + 2Fc*Cy*; 



ef ODpfMr. (S«9 Iftipitrii aiul Flatkiom-mstau.) 



knI nith<?(i1un)) U fiui*d with 11 pt, rfanWo «f 

. itiiy uf wat.r, wud ih» jreUow flUralP (after 4II 

iiliUfl hydrTMhlofic acid). 1* pfMlplUtKl by aul. 

3i»tit]|t m^lnljr of pluUinuicyaaklc and iriillocynHlUiB 



£22 



CYANIDES OF IRON* 



but tbifi fiolutioD decomposes on eTHporatdoQt becoming c&reted witli a film of pnismaa 
blacv and giriiig off cyanogen or chlorine gas, ftcconliraff ai tho cjunide or the obloride 
10 in exeess. NeLtber is ferric cyanide obtained bj aadlllg cyaniilo of potaannm to 
ferric chloride, the prodncts formed being chloride of potoarium, free hydrocyamc acid, 
and A precipitate of ferric hydrate. 

Some of the compotindB ^led prussian bin oshjaiTe the composition of cyamdea of 
iron, intermediate between the proto- and sesquicyamde ; bat, from their mode of for- 
mation, they ajipeAr rather to bo double ryunides. 

The protocyanjde and sesquicyanide of iron unite with other metallic cyanides^ fonn- 
ing two TCiy important groups of compounds, viz, : 

Fenocyanides 4MCy.Fe'Cy» « M*Fe'Cy*. 

F:^?c;:J^S.°l3MCy.Fo.C^ - M-FCCy.. 

It will be seen from thone furmuloe that the feno- and ferri-cy&nidea dlfTcr from one 
another only by one atom of mctul ; and, aocordingly, it is fotmd that the former are 
easily converted into the hiiter by the ii4*tio& of ojdmsing (metal-abstiactiBg) agenta, 
and the latter into the formt^r, by the iiction of reducing (met^il-addiiig) agent*^ Thus 
ferrocyauide of potasaium, K*F^^Cy*, is ejisily converted into the fcrricyauide, K'Fe^Cy*, 
by the action of chlorine, and many doahle ferroeyamdcfi may be formed from ferri- 

cyanides by the action of alkalis in presence of a reducing agent, <r.y. jr, I Fe*Cy*, from 

K'Fo^Cy*, by the action of ammonia in prosenca of grape^sngar. For the aereral viowa 
entertained respecting the compoaitiozi of these d0tu>l6 ^amdasi aee psge 201. 



• X^errooyaiilile*, M^Fe^Cy*, 

Ft*rrf>prHmatf*, Btfdrtferrocyanates, - The general formuLiD of these compotuida 
might evrdiMidy bo balvcil, and, in fact it is oflc^n more convenient to represent them by 
the wimpirr fnrniulu^ ?il"l*i Ty* ; but the tetrabasie formula is justified by the eadslence 
of doul>li> firrncyunidrs coutaininj^ three ut^mB of one metal and one of another, aucb 
as (Nir)K*Fe-Oy*; and, aa already observed, it has the advantage of showing deoriy 
the ri*Uition between the ferro* and ft^rrieyanides. 

The ferrocyanides of the alkali-melals are obtained by neutralising ferropnissic acid 
witli cau«?tic alk^iliH or alkiiUne carbonates; by dissolving ppotocyanide of iron in 
aqueous solutions of alkaline cyanides, or in a mixture of alkatine carbonate and liy- 
drotyanic acid ; by treating protocyauide of irxm, or a mixturo of that compound with 
the H^'Hquicyiniido (pmswan blue), with ao aqueous alkali, whereby protoxide or se^jui- 
oxide of iron is fonin'd ; or by treatiii|T protoxide of iron witli the aqueous solution of 
the cyanide of an alkali -mot al, in which it diswilves with formation of alkalL The 
insoluble ferrocyauidefl. are obtained by precipitating a soluble feiT»:tcyanido with the 
solution of the salt of an earth -metal or a hea^-y metal : e.ff* the eoppor-corapound: 

KTuCy» + Cu'SO^ - CuToOy" + K*SO\ 

The ferrocvanidea of the alkali-metals are colourless in the auhTdrons, but yellow Id 
tllo hydra tod stute ; they ezart no aotioii on Tegetuble colotus^ haTO a faintly saline 
and bitter taste, and do not exhibit the riolent aetton of hydrocyanic acid on the 
animal economy* The ferrocyanides of the eorth-metalfl ore white, and among those 
of the henry metals, some are white, while others arc diatinguLihed by bright coloorB. 
Honce the use of alkaline ferrocyanides to diueover the presence of titanium, tantaliuo, 
ijiolvhdenum, uranium, cobalt.^ nickel, and copper; but antimony, tellnrium, platinam, 
rhodium, and iridium are not precipitated liy alkaline ferrocyanides, 

TliOfto ferrocyanidei? which are deprived of all their water by a gentle heat, are 
doeomffoscd at a higher tempeniture in the fallowing manner: the cyanide of iron £a 
alwA^YN conyi'rted into carbide cf iron, with evolution of nitrogen gas ; but the othef 
eyiiuubi whirh is associated with it, eitht^r remains uiidecomposed, which is the case 
with rvftuiilo of i»ota*8ium, or is resolved into nitrogen and a metallic carbide, as with 
cyanide of leud ; or into cyanogen gas and metal, as with cyanide of silver. If, how- 
evtTj the feiTncyanides are not completely dehydrat^'d before being subjected to 
d4«iifni*'hve fliMtillation, thry give olf hydrocjauic acid, carbonic acid, and ammonia, 
and b*ave tlm tvro frn'tnlji ct^mblned or inuced with a greater or smaller quantity of 
mrUm. In t}i<* eireuit fjf th« voltaic battery, the aquet>ua solutions of the alkaline ^ 
feproeyiinidef< yt^dd alkjUi at the negative pole, and hydroc^'anic acid and prussian blua 
At tliti |M>Nitiv«* |M>U<, iinle.si^ the positive polar wire is of copper, in wluch ease tha 
depip»ii( Ihnrit fiirruid ci hi n i«l j* ( d' cyanid e of copper (Porret t). When ferrocyanides aio i 
UmUil with m\ it( vilritd (ou U'mperature much above 100* C, they give off, with strong 




FERROCYAKroES. 



223 



I and carboui<? aiihydndes» and nitTogen, leaving a comjKinnd 

' ^Ipliurie iid*i with ammonia, oxide of iroa^ find the oiudo of the other Toctid 

iBcnseliui). Betides the gn«c« just mentioned, a large quantity of carbonic oxidt? ta 

voh'tnl, and a sin all quantity of aulphute of ammonium volatilistjs (Bun sen, Pogg, 

Lnn. 3nxiv. 132). See FEknocTANiDB of PoTAASiuif. The §tron^r utidii withdraw 

'de other meUl man ferroeyanides, and tbereliy separiite ftzrroprussic acid ; 

FbTeCy* + iPSO* - H^TeCy* + Pb'SOS 

u ftimtlar pffect is produced by sulph rdric acid, if the other metal be precipitable from 
» tolulions by tliat reagent. Many ferrocyanidps of heavy metals are decompoaed by 
> alkaliB} yielding an alkaline ferrocyauide and a hydrate of the heavy metal: 

Cu^FeCy* + 2H:H0 = E^cCy* -^ 2CuH0 

prilher aUudiB nor Bulphydric acid decompose the cyanide of ii-on contained in ferrO' 
yanidee. 

[ Most f€itToc^anide8 unite in their t»ntir<* state Tvith Btrong sulphuric acid, fonnlne a 
kind of salt, m which they conetituto th^ base. Their powder soaked in ct)ld oil of 
pitriol BH'c4L* up to a paaty compound^ with loss of colour, and conaidemble ovolution 
T heat, and, according to the natnre of the metiil present^ either dis^iolvefl completely 
I m IjLTge exceaa of the acid^ or remains almost undistiolved^ forniini; a solid compound 
rith it. T|ieae eompounda remain undecomposwl even at temperatures much above 
' "^C. If a small quantity of water be added to the resulting solntiona^ e.tf, by ex- 
j them to die air, tb(>y frequently deposit a crystalline compound, which contaioB 
i «alphnnc acid, and when treated witli a larger quantity of water, is resolved either 
pto ferropmasic acid and a compound of sulphuric acid with the other metallic oxide, 
for into metallic ferrocyauide and dilute sulphuric acid. (BefzeliuB^ Schw. J. 
U.) 



Fsfi&ocTANiDEOPAi.uMiNiux, obtai nod by saturating ft-rrocy anido of hydrogen 

Ip^rmprofieic acid) with aliunina, in uncrystallisablo, and dccompos^pa by evaporation. 

FerroCTanide of potassium added to an alumiuium-^alt, even if strongly acidulated, 

fctfowt down the whole of the aluminium in the form of a white precipitate, which 

ric^ldft by analysis 14-87 per cent, aluminium, and 2'2-36 iroUj and may therefore bo 

ntcd by the formula 2Al*Cy*.3FeCy, or (Ali)«.Fe*Cy* (calc, 1470 aluminium, and 
S'5.1 ironX which is that of a prussian blue (p. 329) in which part of the iron (thut 
hieli enters us ftrHcum) i« replaced by an eq^uivaleut quantity of altimiiiiimL (C. 
Tisftor, Comptw rend. xlv. 232.) 

Fan ft OCT AX IDS ofAumoxiux, (NH*)*Fe*Cy* + 3 aq., is obtained by saturating 
SToprusic acid with ammonia, or by decomposing ferrocyanidc of lead with Ciirbouatc 
r smnioQia, and precipitating the filtered solution with alcohol, as the salt would be 
ompoeed by evaporation. It forma pale yellow, transparent, octahedral crystals of 
dimetric system, isoTOorphous, or rather bomtcomorjjhona, with ferrocyauide of 
Dlaasiam. Oroinary combination P . oP. 3>ength of principal axis — 1*789, Incli- 
ation of P : P in the terminal edges = &7*^ 46'; in the lateral edgt^ ^ 136^ o2'. 
th»»y are permanent in the air, Tery soluble in cold water, insoluble in alcohol. 
~ I solution of this salt mixed with chloride of ammonium and concentrate!, yielda 
* Ind crystaJaof CfUan/trrort/anidr of ammonium, ( NH*)*Fe*Cy*.2NH*Cl > 3 aq., 
_ transparent, with a yellowish colour and glassy lustn*, permanent in the aic 
soluble in water. The crystala ore sometimes rhombohedrons R, tometimea 



Fiff. 360. 



Ilbrm of the next acut<*r rhombohedron, — 2R. soroetimcH 
^rnbination R . oR, -2R {Jif/. 360). Length 
^ for R » 10325. Inclination of the faces 
._ the terminal e<:lges of the hexagonal pyra- 
btd. - 96^^ 62 ; R : oR = V29'59; R: -2R - 126° 69'; 
2R t oR *= 112** 46*. The solution is decomposed by boil- 

and deposits cyanide of iron. (Bunsen.) 
Th» analogous compound, Bro^o^fcrrocyanid^ of tttn/mo^ 
, (NH*j*FeCy» 2>'H«Br 4 3 aq. likewise forms rhom- 

iril crystals permanent in the air and very soluble in 

^if^. They exliibit the same faces as those of the preceding compound, but with dif- 
^•nt inclinations, the rhombohedron — 2R also predominating. Length of principal 
» for K - 0-9H68. Inclination of R : R in tbe terminal edges '^''° ^'^' "'^ * 
|— 2R *s. 1b^ 6'. (Himly and BnnaeUf Pogg. Ann. xxxviii. 20S.) 




98° 49' J -2R: 



yrrrvcyanieU of Amuwnium anil Putatsiam, 5*, | FeHy.— Obtained by tli© tfition 



224 



CYANIDES OF IRON. 



of animo&ia on femcjaaidB of potaesimn m presBDce of reducing agenba^ Bwch as 
grap^ or milk-eugiir : 

2K"Fe«(y + (NH*)«0 - O « 2(NH*)K*Fe*Cj«. 
Tha ammonia ehould be poiirt»d on u mixture of about 20 pta* femcyanide of potas- 
sium to 1 ptt sugar ; the mixture left to stand for some days in a loosely stoppered 
bottlf* and frequently shaken ; and when its colour baa cbangied to a pure yellow, the 
Kilt should be precipitated by alcohol and recryBtallisod from inrater, as it in liable to 
decompose if eraporated in presence of the reducing agent, The salt forms pale 
jellow Bquare nriiinuit easily soluble in cold, and still more in hot wiit<*r. When heated. 
it gives off hyarocyiuiic acid and cyanide of ammonium. With niBtallic nalts it yields 
the samo precipitatos as ordinaiy yellow prussiate. Heated with fijcod aUcaIis» it 
pros ofTamrannift and yields aalta of similar constitution; e, ff, with soda, the salt 
K*Nal^t5^C>«. (Reindel, J. pr, Chem. Ixv, 450.) 

Another ferrocyanido of ammonium and potaasi^un^ (NH*)'K'Fe'Cy*, is obtainiKl by 
decomposing the corresponding barium-salt^ Ba*K*Fe'Cy*, with sulphate of wmnoninm ; 
or by action of ammonia ou fenrocyanide of iron and potuasium : 

^^*!Fe=Cy« + 2(NH^.H.O) « ^j^hVI^'''^^ '^ 2(FgHO). 
(Reindel, J. pn Chem. kxd^ 342.) 

FERaooYANinB OP Babium, Ba 'Fe-Cy* + 6 aq. — Ob tained by saturating fcrro- 
pnissic acid with baryta-water or carbonate of barium ; by decomposing prussian blue 
with baiyta-watcr at the boiHng heat, liltj^ring at the same temperatnne and leaving 
the solu^on to cryatidlise ; or by decomposing a solution of ferrocyanido of potassimni 
with chloride of burinm at tho boding heat, the latler b^ing used in considerable 
excess (more than 2 at. chloride of barium to 1 at of the yellow prussiat-e), and acain 
boiling the crytttalline powder which separates on cooling, with chloride of bantiin. 
If tho chiorid^u of barium is not preseut in considemble exo^a, a double ferrocyanide 
of biirium and |)otassium is produced. 

Ferrocyanido of bsirium may also be produced by the action of ferroaa sulphate on 
cyanide of barium (6BaCy + Fe=SO* = Ba*Fe*Cy* + Ba*SO*X which, according to 
Margucritto and De SourdoTid (p, 203), may easily be obtained by passing « current 
of air over an ignited mixture of charcoal and carbonate of barium. If this proceas 
should fulfil the expectations of its authors, ferrocynnide of barium may take the place 
of tlie poUissiura-salt for the preparation of certain ferrotyanides used in the arts, 
being ea-sily conTerted into fyrroprusaic acid by the action of dilute sulphuric acid, into 
prusBian blue by ferric salts, &e. 

Perrocyanide of barium crystaUisea in fattened, oblique, rectangular, monodinio 
prisms, yellow, non-effl orescent, soluble in 584 pts, of cold and 116 pts, of boiling 
water (Buflos). At 40° C, they give off yi of their water, and become will to ajid 
opaque, the remaining ^ not being evolTcd till the s^ult begins to decompose. At a 
red heat, it gives off nit4x>geii, and leaTes a mixture of oarbide of iron and carbide of 
barium, or, if in contact with the air, amixturo of ferric oxide and carbonate of bariam. 
On piu^sing chlorine through tho aqueous solution, it becomes turbid, acquires a 
grecnish^yellow coh^ur, deposits a greeo powder, then becomes brown and dafk*red, 
and is docomjKJsed by evaporation, depositing a bluish- wMto powder, but no 
crystals. 

FtTrocyanide qf Barium aiid Potassium^ {Ba'K')Fe'Cy* 
+ 3 aq., is produced by mixing tho boiling concontrated 
flolutioos of 2 pts. ferrocyjinide of potassium and 1 pt. 
chloride of biinum, and ctyet^illiscs on cooling in small, 
light-yellow rhomlx>hedrons, truncated by the face oR. 
Length of principal axis *- r670. Inclination of R : R 
in terminal edges = 08° 33'; It : oR - 118^ 63*. 

The ciyatuls dissolye in 3B pts. of cold and d*& pts, of 
boiling water. 

By treating the solution of this salt with soluble sul- 
phates, a number of other double ferrocvanides containing 
potassium may be obtained ; thus, ivith sulphate of am- 
monium : 
Ba'KJFeK]j' + (NH^)»SO^ = Ba^SO* + (NH^j^K^Fc'Cy*. (ReindeL) 

The acid milphates of the alkali*metiik, in presence of an oxidising substance^ oon»^i 
vert it into ferricyanides of alkali-mettd, thus : 

2Ba'K^e-Cy* + 2KHS0< + O = 2K«FeK}y« + 2Ba«S0* + H^-0. 

(Reindel, J. pr, Chom. btxvi. 342.) 



Fig. 361. 




FEEEOCTANIDES. 225 

FsBBOCTANiDX OF B18XUTH. — ^Nitrate of bismuth forms with fBrrocjanide of 
potassium a white, yellowish-white, or yellow precipitate, which afterwards turns green. 
It dissolves in nitzic acid, and is precipitated therefirom by water. 

Fbbbootamxdx or Cadmium is a white precipitate soluble in ammonia. 

FsBBCCTAiriDB OF Calcium, Ca*Fe»Cy* + 12 aq., obtained by boiling prussian 
blue with milk of lime not in excess, evaporating the filtrate to a syrup, and leaving it 
to dystallise, forms large flattened rhombic prisms, of a light yellow colour, veiy 
bitter and disagreeable t^rte, veiy soluble in water, insoluble in alcohol. 

Prussian blue, boiled or digested with excess of lime, yields basic compounds, or 
oryferrocyanides of calcium, (Gm. vii. 482.) 

Ferrocyanide of Calcium and Potassium, (Ca*K*)Fe*Cy' + 3 aq., is obtained as 
a yellowish-white crystalline precipitate on adding ferrocyanide of potassium to a 
aomtion of a calcium-salt, not too dilute. 

Fbbboctanidb of Cbbivm. — ^White precipitate. 

Fbbbootanidb of Cobalt, Co*Fe*Cy*. — Pale blue hydrated precipitate, which, 
when carefully heated, gives off the greater part of its water, and assumes a dark greeu 
edour. If it be then heated to 360° C, it becomes light green, giving off water and a 
small quantity of cyanide of ammonium. When more strongly heated in a close vessel, 
it gives off nitrogen, and leaves a mixture of the carbides of iron and cobalt, which 
g^ws when raised to a higher temperature. The compound dissolves easily in strong 
sulphuric add, forming a red liquid, which, after some time, deposits sulphate offerro* 
evanide ofeobalt, as a rose-coloured, oystalline powder, which is decomposed by water 
(^erselius). Ferrocyanide of cobalt dissolves in ammonia and in car Donate of am- 
Bionia (Wittstein), not in sal-ammoniac. (Brett.) 

Fbbboctakidbs of Coppeb. Cuprous Ferrocyanide, Ccu*Fe*Cy*. — Ferro- 
^anide of potassium added to a solution of cuprous chloride in hydrochloric acid, throws 
^wn white flakes, which, when exposed to the air, or to the action of chlorine-water, 
become purple-red, and are converted into cupric ferrocyanide (Proust). Cuprous 
ferroc ya nide is likewise obtained by the action of acids on the following compound 
(Schulz). It dissolves in ammonia, but not in ammoniacal salts. (Wittstein). 

FotoMsio^uprous Ferrocyanide, Cu*KTe«Cy« + 3aq. =. ^^j|Fe«Cy« -»- 3aq.— 

When precipitated cupric fenocnranido is added to a solution of cyanide of potassium, 
cyanoffen is evolved, and a light j^ellow solution is formed, which, if the cyanide of 
potassium is not in excess, deposits, first a deep red precipitate, and after filtration, 
smaO square prismatic crystals, of a da>k red-brown colour, and having the composition 
indicated by the above formula. This compound is more easily obtained by dropping 
a solution of cupric sulphate into a mixture of cyanide and ferrocyanide of potassium, 
then heating the liquid and leaving it to itself. The crystals give off water at 100° C. 
and turn black ; the^ are insoluble in water, ether, and alcohol, but soluble in cyanide 
of potassium. Boibng water decomposes them, with formation of ferrocyanide of 
potassium. Acids also decompose them, separating white cuprous ferrocyanide. (C. 
Schnls, J. pr. Chem. IxviiL 257.) 

Cyanide of Potassium, Cuprosum and Ferrosum, (K'Ccu*Fe*)Cy^ + 4 %.(]. — ^A liquid 
oonsistiiig of cyanide of potassium and sulphate of copper containing iron, which 
had been used for coppering by electrolysis, and had stooa for a long time in an im- 
pc^ecUy closed vessel, was found to have deposited brown-red octahedral crystals, 
resembling chrome-alum, and agreeing in composition with the above formula. The 
same salt was obtained, in the form of a chocolate-coloured powder, by boiling cuprous 
cyanide with solution of ferrocyanide of potassium, and leaving the liquid to cooL 
(Bolley and Moldenhauer, Ann. Ch. Pharm. cvi. 228.) 

According to Moldenhauer^s analysis, the crystals contain 4 at. water ; according to 
W. J. Wonfor (Chem. Soc J. xv. 357), they contain 5 at. water, and have the foni^ 
of the cabo-octahedron {fig, 176, p. 124). 

[For Kuhn's experiments on the action of ferrocyanide and ferricyanide of potassium 
on the oxides, sulphides, and cyanides of copper, see Ann. Ch. Phurm. Ixxxvii. 127.] 

Cuprie Ferrocyanide, Cu*Fe*Cy*. — ^Ferrocyanide of potassium added to excess 
of a cupric salt forms a dark purple-red precipitate. The liquids, if concentrated, 
solidify in a magma when stirred ; if more dilute, they yield thick flakes ; and if veiy 
dilute, the mixture assumes a beautiful red colour. This precipitate, even when a 
large exeew of copper-salt is used, carries down with it a large quantity of ferro- 
cyanide of potassium, which cannot be removed by washing. If, therefore, the 
precipitate be suspended in water, and decomposed by sul^urettad hydrogen — 
which takes a long time — a strongly acid liquid is obtained which, like ferroprussie 
add, depodtt prossian blue on exposure to the air, and forms a blue predpitate with 

roL.IL Q 



226 



CYAKIDES OF IKON. 



ferric saltji, hut is not pwcipiuted by ether, exc(^pt on addition of hydrochloric acid. 
It coDtuins H'KPe^Cy" (WiUiamaDn. Ann. Ch. Pharm. Ivii. 246). According to 
Ifi&mmel&bprg ^Pogg. Ann. Ixxir. 05), acetate or 8iilpliiit« of copper mixed with ferro- 
pmasic acid yields pore ferrocyaaide of copper, which, after drying over stilphnric acid, 
contains Cn*FeK/y* + 7 aq.. ; according to Monthiera, however^ it contains C?u*F8*Cy* 
+ 9 aq. 

The salt givei up only a part of its water when gently heated^ and at a stronger 
heat evolves hydrocyanate of ammonia aa well a» watt^r (Vanqnolin), also carbooat^ 
of ammonia and nitrogen gas (BerEelius). The residua, if more strongly heated in 
a ivtotty exhibits a faint glow, and appears afterwards to bo compo«M of I at bicar- 
bide of iron aud 2 aU moAocarbide of roppcr (Berzelius). Aqneous potash decom- 
poaes the salt, produeing ferrocjanide of potassium and hydmfed cnpric oxide (Ittner). 
In oil of vitrioL which dissolves but little of it, the salt assumes a greenian yellow^ 
whit« colour ; hut on subsequent immersion in water, which withdraws the sulphimc 
acid, it resumes its dark red colour (Berzelius). It is insoluble in wat«rand in acids* 
which do not decompose it; also insoluble in ammoniacal salts* (Brett, Wittstein.) 
It dissolves, however^ in aqueous ammonia, forming a colourless solution^ which, on 
evaporation leavea the cupric ferrocyanide with its original colour^ Thia reaction 
affords tha means of detecting extremely small quantitiea of ooppoPi <sren when 
associattHl with nth er m etaia. ( W ar i n g t o n. See p, 56. ) 

Diammonio'^cuprie Ferroctfanide^ 4NH*-Cu*Fe*Gy* + aq., or Ferroeuamde of Cu- 
pramjjwfuum^ (NH'Cu)*.Fe*Cy* + aq. — Produced by adding ferrocyanide of potusaium 
to a solution of nitrate of cuprammoniaim (or of any cupnc salt containing suflScient 
ammonia to form a clear solution). It is a pale yeUovir crystalliuo preeipitute, soluble 
in free ammonia, insoluble in watar or alcohoL Dilute acids withdraw the ammonia, 
leaving red- brown cupric ferrocy anida, (M o n t h i e ra, J. Ph&rm. [3] xL 24 9 ; B li n s <; n , 
Pogg, Ann. Txxi>« 134.) 

thiammtmio^uprw Ftrrocji/anidr, 8NH'.Cu*Fe-Cy*, or Ftrrocyanide of Ammo-cu- 
prammonium^ P^»H"(NH*)Cui*Fe*Cy* — Cupric ferrocyanido, or the preceding ammonin- 
oomponnd in tiie moist stat^?, absorbs ammoniacal gii3, assuming a green colour and 
being converte*! into the octammomo-comfwund. The latter is very unstable, turning 
yeUow and giving off half its ammonia on exposure to the air» (Monthiers.) 

PoimHo-cu^ric Ferrocyanide^ Cu^K*Fe*Cy* — Produced, according to Mosander, l>y 
adding a cupnc salt, drop by drop, to excess of ferrocyanide of potassium. [According 
to Kammelsberg, howeveTi (Pog^. Azm. bnciv. 06), the precipitate thus formed con- 
tains water and is composed aoooraSng to the improbjihle formula Cu*Fe'Cy».K*Fe'C;^* 
-I- 2 aq. When, on the other hand, the ferrocyanide is dropt into excess of the cupric 
salt, the precipitate has the compoaition 2(Cu'K'F©*Cy*, aq.) + 9(Cu*FoK;y*. 7 aq.) 
Jahresben d. Cbem. 1847-8.] 

The compound Cu'E^e^Cy* also oonstitutes the dark red precipitate mentioned as 
produced in the preparation of potaaaio-cuprous cyanide, when a comparatiYcly small 
quantity of cyanide of potassium is used. (Schuls.) 

The corresponding sodium and ammtmium compoands sre obtained in like manner. 
The latter, Cu*(NH'*)*Fe*Cy\ is a scarlet oystalline body, which turns brown on dry- 
ing. (Schuix.) 

FsMBOCTANini or Etrti^ {C7'H')*Fe'C3r*. — When hydrochloric acid gas is 
passed into a weU cooled alcoholic solution of ferroprusAic add^ oolouilesa a^j^itals are 
obtained which, aft<*r drying for a certain time over lime^ oonatat of (C'H*)*Fe*Cy* 
+ 2C*H*Cl + 6 aq. Their concentrated alcoholic solution, mixed with ether, deposits 
nacrf*ous ciystab of pure ferrocyanide of ethyl. (C*H*)'Fe'Cy* -♦- 6 aq. Botii compounds 
become anhydroiia by eontiuued exposure over lime. The corresponding methyl and 
am^/-oompounds appear also to exist. (H. Buff, Ann. Ch. Phaim. z:cL ^3.) 

Ferrogtanidb or Htdboosn. Fcrropruttic or H^dro/erroeyanie 
acid, H*Fe*Cy* =^ 4HCy.2FeCy. FerrureiUd Chtfa:ne acid. Eisenblavgdure, IFiw- 
*rrgtoffriMencyafiur^ Ferrocyanwasserstq^sdure, This acid, discovered by Porrett 
(Phil, Trans, 1814, p. ft2f)v is obtained by decomposing ferrocj-anide of barium with 
sulphuric acid, ferroc^nide of potassitmi with tartaric acid, ferrocyanide of lead or 
copper with aolphydnc acid, or pmssian blue with Tery strong hydrochloric acid ; 

F«*'Cy" + 12Ha = 3H«Fe*Cj« + 4Fe*Cl*. 

A good method of preparing it is to dissolv© ferrocyanide of potassium in a small 
quantity of water, boil the solution to expel the air, leave it to cool in ft stoppered 
bottle, then mix it with strong hydrochloric acid, also freed finom air, and shake up the 
liquid with ether. The ffrropmssic acid is then pftHjipitatM in thin white scales* 
which may 1^ collected on a filter, washed with ethei^aloohol, pr««sed, and dried in vacuo 
OTer suipburid acid (Posaelt^ Aon. Ch. Pbann.xlii. 163> It is better to separate the 



I 



FEBBOCYANIDES. 227 

acid from its solution by precipitation with ether than by evaporation/ as the solution 
decomposes when exposed to the air. If the aqueous solution of ferrocyanide of potas- 
nun be miked, first with ether, and then with hydrochloriQ acid, the ferropmssic acid 
separates perfectly white, and may be dried without becoming coloured. It may then bo 
farther purified by pressure, solution in alcohol, and precipitation with ether (DollfiLB). 
Kuhlmann prepares fenoprussic acid on the large scale by decomposing ferrocyanide 
of barium witn an equivalent quantity of sulphuric acid. The clarified solution is 
preserved in well closed stone-ware jars and sent in that state into the market 

Ferropmssic add crystallises in white grains or small interlaced needles: larger 
orystals are deposited from an alcoholic solution covered with a layer of ether. It is 
easily soluble in water and alcohol, insoluble in ether. When exposed to the air, it 
absorbs o^gen, even at ordinary temperatures, and more quickly when heated, hydro- 
cyanic add being set free and prussian blue, Fe^*Cy", deposited: 

7H«FeKy + 0» - 24HCy + 2HH) + Fe"Cy". 

(Beiman and Car ins, Ann. Ch. Pharm. cxiii. 39.) 

This reaction is applied to the production of prussian blue in calico-printing. The 
pattern is printed wiUi a mixture of ferrocyanide of potassium with tartaric acid, or 
with sulphuric add and alum, and exposed to the action of a hot steam-bath. In this 
treatment^ fenoprussic add is first set free, and then decomposed in the manner just 
chained. 

Ferropmssic acid is a strong add, having a sour taste, reddening litmus, and 
deoompoeing carbonates and acetates without the aid of heat: it even decomposes 
tartrates and oxalates. With most metallic salts it acts in the same manner as ferro- 
cyanide of potassium. Heated with mercuric oxide, it yields cyanide of mercury and 
protocyanide of iron : 

H«FeKy + 2Hg"0 - 2Hg''Cy« + 2FeCy + 2H«0 ; 

but the fenous cyanide is immediately oxidised by the excess of mercuric oxide, with 
•eparation of metallic mercury. 

Fenoprussic add is tetrabasio, as appears from the constitution of some of the 
double fenocyanides ; e. g. K*(NH*)Fe*Cj^, and from the relations between the ferro- 
and ferriqranides (p. 222). 

Fbbboctamidb of Ibom. Fbbbio Fbsbootanidb, Fe'Cy* + 9 aq., or 
nther Fe>H:Jy" + 18 aq. - (Ffe'^'FeKJy'* + 18 aq. - fe«Fe*Cy» + 6 aq.*— This is 
one of the compounds designated by the common name of Prussian blue. It is obtained 
in the pore state by predpitating fenoprussic add with a ferric salt : 

3H«Fe«(y + 4Fe«a« = 12HC1 + Fe»*Cy»« 
or 3H*Fe^ + 2Fe*(SCM)» - 6H«S0* + Fe»*Cy>«. 

The same predpitate is formed by adding ferrocyanide of potassium to a ferric salt, 
the latter being in excess; it always carries down with it a certain quantity of the 
alkaline ferrocyanide, which, however, may be removed by digestion with the ferric 
■alt and subsequent washiog. If, on the contrary, the ferric salt be added to excess 
of the alkaline ferrocyanide, a mudi larger quantity of the latter is carried down with 
the predpitate^ and cannot be completely separated by any amount of washing 
(p. 229). 
The pure ferric ferrocyanide obtained as above is sometimes called Pari$ blue. 
Feme fenocyanide is likewise produced by the following reactions 

0. By predpitating a fenoso-ferric salt with cyanide of potassium : 

9KCy + 8Fea + 2Fe«a« - 9KC1 + Fe»Cy»; 

if the izon-flolution contains a larger proportion of ferric salt, the excess of the latter 
does not appear to alter the character of the precipitate ; but if the ferrous salt is in 
excess, the predpitate will have a different character, approaching to the compodtion 
of fenons fezricyanidd, or Tumbull*s blue. (See FsBwcTAiriDBs.) 

b. By mixing hydrocyanic add, first with potash, then with a ferroeo-ferric salt, 
and then with excess of hydrochloric add. In this case, fenocyanide of potassium is 
first formed, and this with the ferric salt present forms pmssian blue. Tnis is one of 
the chief tests for hydrocyanic acid (p. 218). 

c. By immeraing recently predpitated ferroso-ferric hydrate in hydrocyanic add. 

d. Br immersing ferrous cyanide in a solution of a ferric salt^ which is thereby 
ledoced to a ferrous salt : 

9FeCy + 2FeKn« - 6FeCl + Fe»Cy». 

• FfB a Fa* s 66 ; /r s |Fe B 18}. 
Q2 



228 



CYANTOES OF IRON. 



«. Bj the aclioD of air, chloriBe-water^ or other oxidising ig«Qta^ on fbrroos cy^smde : 

ISFeCj + 0* - re»*Cy»» + Fe^O*; 

or, on ferrocjanidQ of hydrogen : 

7H*FeKy +